Peritoneal dialysis after surgery for congenital heart disease in infants and young children

Peritoneal dialysis in infants and children after open heart surgery

BACKGROUND

Infants and children who undergo surgical repair of complex congenital heart diseases are prone to developing renal dysfunction. The purpose of this study was to investigate the risk factors associated with prolonged peritoneal dialysis (PD) and the mortality of pediatric patients with acute renal failure (ARF) after open heart surgery.

METHODS

From June 1999 to May 2007, a total of 542 children underwent open heart surgery for congenital heart disease. Fifteen (2.8%) experienced ARF and seven (1.3%) required PD. The clinical and laboratory variables were compared between the survivor and non-survivor groups of ARF patients that needed PD.

RESULTS

The non-survivors (n=3, 43%) had a Longer cardiopulmonary bypass time (154+/-21 vs. 111+/-8 minutes, p=0.012) and longer aorta clamping time (92+/-40 vs. 66+/-15 minutes, p=0.010) than the survivors (n=4, 57%). Before the PD, the pH and base excess of the arterial blood gas analysis in the survivors was much higher than that non-survivors (7.30+/-0.04 vs. 7.16+/-0.10, p=0.039; -5.15+/-3.13 vs. -12.07+/-2.9mmol/L, p=0.031). Furthermore, the survivors had a shorter interval between the onset of ARF and the day the PD was begun (1.2+/-0.4 vs. 4.3+/-1.2 days, p=0.001), and shorter duration of PD (6.6+/-2.7 vs. 13.0+/-3.5 days, p=0.036) than non-survivors.

CONCLUSION

Early intervention with PD is a safe and effective method for managing patients with ARF after open heart surgery. The cardiopulmonary bypass and aortic clamping duration, time of initiating PD, duration of the PD, sepsis, and relative complications may predict the prognosis of these patients.

Cardiorenal syndrome in children with heart failure

Concomitant cardiac and renal dysfunction has been termed the cardiorenal syndrome (CRS). This clinical condition usually manifests as heart failure with worsening renal function and occurs frequently in the acute care setting. A consistent definition of CRS has not been universally agreed upon, although a recent classification of CRS describes several subtypes depending on the primary organ injured and the chronicity of the injury. CRS may develop in adults and children and is a strong predictor of morbidity and mortality in hospitalized and ambulatory patients. The underlying physiology of CRS is not well understood, creating a significant challenge for clinicians when treating heart failure patients with renal insufficiency. This review summarizes recent data characterizing the incidence, physiology, and management of children who have heart failure and acute kidney injury.

A small post-operative rise in serum creatinine predicts acute kidney injury in children undergoing cardiac surgery

To predict development of acute kidney injury and its outcome we retrospectively studied children having cardiac surgery. Acute kidney injury (AKI) was defined using the serum creatinine criteria of the pediatric Risk Injury Failure Loss End-Stage (pRIFLE) kidney disease definition. We tested whether a small rise (less than 50%) in creatinine on post-operative days 1 or 2 could predict a greater than 50% increase in serum creatinine within 48 h in 390 children. AKI occurred in 36% of patients, mostly in the first 4 post-operative days. Using logistic regression, significant independent risk factors for AKI were bypass time, longer vasopressor use, and a tendency for younger age. Using Cox regression, AKI was independently associated with longer intensive care unit stay and duration of ventilation. Patients whose serum creatinine did not increase on post-operative days 1 or 2 were unlikely to develop AKI (negative predictive values of 87 and 98%, respectively). Percentage serum creatinine rise on post-operative day 1 predicted AKI within 48 h (area under the curve=0.65). Our study shows that AKI after pediatric heart surgery is common and is a risk factor for poorer outcome. Small post-operative increases in serum creatinine may assist in the early prediction of AKI.

Acute kidney injury in an infant after cardiopulmonary bypass

The infant who develops acute kidney injury (AKI) after cardiopulmonary bypass (CPB) surgery presents unique challenges and opportunities to the clinician and to the investigator interested in the study of AKI pathophysiology. Infants do not have many of the comorbid conditions that confound CPB outcome studies of adults. Because the timing of the AKI event is known in this clinical setting, collaboration between cardiology intensivists, nephrologists, and perfusion technologists is essential to minimize the impact of CPB on the kidney. Early institution of ultrafiltration in the operating room and renal replacement therapy in the postoperative period may decrease the proinflammatory milieu and its resultant systemic effects. In addition, early initiation of renal replacement therapy to prevent fluid overload may result in improved infant outcomes.

Progression from acute kidney injury to chronic kidney disease: a pediatric perspective

Although emerging evidence indicates that the incidence of both acute kidney injury (AKI) and chronic kidney disease (CKD) in children is rising and the etiologies are dramatically changing, relatively little is currently known regarding the potential for transition from AKI to CKD. In both situations, early intervention can significantly improve the dismal prognosis. However, the lack of a uniform AKI definition and the paucity of early, predictive biomarkers have impaired our ability diagnose AKI early to institute potentially effective therapies in a timely manner. Fortunately, recent data has validated a multidimensional AKI classification system for children. In addition, the application of innovative technologies has identified candidates that are emerging as early biomarkers of both AKI and CKD. These include neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and kidney injury molecule-1. Studies to validate the sensitivity and specificity of these biomarkers in clinical samples from large cohorts and from multiple clinical situations are currently in progress, facilitated by the development of commercial tools for the reproducible measurement of these biomarkers across different laboratories.

Medication dosing and renal insufficiency in a pediatric cardiac intensive care unit: impact of pharmacist consultation

Pediatric patients who have undergone cardiac surgery are at risk for renal insufficiency. The impact of pharmacist consultation in the pediatric cardiac intensive care unit (ICU) has yet to be defined. Patients admitted to the pediatric cardiac ICU at our institution from January through March of 2006 were included. Patient information, collected retrospectively, included: demographics, cardiac lesion/surgery, height, weight, need for peritoneal or hemodialysis, need for mechanical support, highest and lowest serum creatinine, ICU length of stay (LOS), renally eliminated medications, pharmacist recommendations (accepted or not), and appropriateness of dosing changes.There were 140 total admissions (131 patients; age: 3.0 +/- 6.3 years) during the study period. In total, 14 classes of renally eliminated medications were administered, with 32.6 +/- 56.4 doses administered per patient admission. Thirty-seven patient admissions had one or more medications adjusted for renal insufficiency; the most commonly adjusted medication was ranitidine. Patients who required medication adjustment for renal dysfunction were significantly younger compared to those patients not requiring medication adjustment. Pharmacist recommendations were responsible for 96% of medication adjustments for renal dysfunction, and the recommendations were accepted and appropriate all of the time. The monetary impact of pharmacist interventions, in doses saved, was approximately $12,000. Pharmacist consultation can result in improved dosing of medications and cost savings. The youngest patients are most at risk for inappropriate dosing.

Acute renal failure and outcome of children with solitary kidney undergoing cardiac surgery

The aim of this study was to investigate the risk of acute renal failure (ARF), the need for renal replacement therapy, and the outcome of children with a solitary functioning kidney undergoing open heart surgery. The study was performed retrospectively on all children diagnosed with solitary functioning kidney and who required open heart surgery between January 2003 and January 2007. Demographic, perioperative renal function and intensive care course data were documented. Eight patients (six females) fulfilled the study criteria and were included in the study. Their median age and weight were 4.5 months and 3.6 kg, respectively. Their mean +/- standard deviation (SD) preoperative blood urea nitrogen (BUN) and creatinine levels were 3.7 +/- 1.6 mmol/L and 55 +/- 10 micromol/L, respectively. Postoperatively, the mean BUN and creatinine levels peaked on the first postoperative day to reach 7.8 +/- 2.6 mmol/L and 76 +/- 22 micromol/L, respectively, before starting to return to their preoperative values. Two out of eight patients (25%) developed ARF after surgery, but only one of them (12.5%) required renal replacement therapy. Open heart surgery on bypass can be performed safely for children with solitary functioning kidney with a good outcome. ARF requiring renal replacement therapy might occur temporarily after bypass surgery in a minority of cases.

Mixed venous oxygen saturation monitoring after stage 1 palliation for hypoplastic left heart syndrome

BACKGROUND

Staged palliation for hypoplastic left heart syndrome has been marked by high early mortality due to the limited cardiac output of the postischemic single right ventricle combined with the inefficiency and volatility of parallel circulation.

METHODS

Since July 1996, we have performed stage 1 palliation (S1P) in 178 patients. Within this group is a consecutive cohort of 116 patients with true hypoplastic left heart syndrome that underwent S1P with a modified Blalock-Taussig shunt. A prospective database containing postoperative hemodynamic data was maintained on all patients. Studied were the incidence of organ failure, extracorporeal membrane oxygenation (ECMO), and mortality, as well as the relationship between these outcomes and postoperative hemodynamics.

RESULTS

Hospital survival for this cohort was 93% (108/116). Patients who died after S1P had a lower superior vena cava oxygen saturation (SVO2) level compared with survivors (53.1% +/-10.6% versus 59.3% +/-9.2%, p = 0.034). Renal failure developed in 2 (1.7%) of the 116 patients, necrotizing enterocolitis developed in 1 (0.9%), and 5 (4.3%) had clinical seizures. ECMO support was instituted in 12 patients (10.3%). The SVO2 level was lower in patients requiring ECMO (54.0% +/- 9.7% versus 59.9% +/- 9.2%, p = 0.031).

CONCLUSIONS

Goal-directed therapy with SVO2 as an indicator of systemic oxygen delivery is associated with excellent early survival and a low incidence of organ failure after S1P. Inability to optimize SVO2 in the early postoperative period is associated with an increased risk of organ failure, ECMO, and death.

Risk factors for acute renal failure requiring dialysis after surgery for congenital heart disease in children

BACKGROUND

Limited data exist on the risk factors for acute renal failure (ARF) following cardiac surgery in children with congenital heart disease. This cohort study was conducted to examine this subject, as well as changes in the incidence of ARF from 1993 to 2002, the in-hospital mortality and the time spent in the intensive care unit (ICU).

METHODS

One thousand, one hundred and twenty-eight children, operated on for congenital heart disease between 1993 and 2002, were identified from our prospectively collected ICU database to obtain data on potential risk factors.

RESULTS

A total of 130 children (11.5%) developed ARF after surgery. A young age [> or =1.0 vs. <0.1 year; odds ratio (OR), 0.23; 95% confidence interval (CI), 0.12-0.46], high Risk Adjusted Classification of Congenital Heart Surgery (RACHS-1) score (OR, 2.72; 95% CI, 1.66-4.45) and cardiopulmonary bypass (CPB) (<90 min vs. none; OR, 2.68; 95% CI, 1.03-6.96; > or =90 min vs. none; OR, 12.94; 95% CI, 5.46-30.67) were independent risk factors for ARF. The risk of ARF decreased during the study period. Children with ARF spent a significantly longer time in the ICU (2-7 days vs. <2 days, P = 0.002; > or =7 days vs. <2 days, P < 0.001) compared with non-ARF patients, and showed increased in-hospital mortality (20% vs. 5%, P < 0.001).

CONCLUSION

A young age, high RACHS-1 score and CPB were independent risk factors for ARF after surgical procedures for congenital heart disease in children. The risk of ARF decreased during the study period. Children with severe ARF spent a longer time in the ICU, and the mortality in ARF patients was higher than that in non-ARF patients.

Postoperative Prophylactic Peritoneal Dialysis in Neonates and Infants After Complex Congenital Cardiac Surgery

Peritoneal dialysis after complex congenital cardiac surgery was introduced to a group of neonates and infants (n = 756; age, 0 to 1 year) between May 1993 and December 2005. Indications of peritoneal dialysis were determined as well as methods, prolonged dialysis, and its outcomes. Demographic characteristics, preoperative risk factors, intraoperative variables, and postoperative complications were compared in 756 cases with ages below 1 year. All cases underwent ultrafiltration during the perioperative stage. One hundred eighty-six cases (24.6% of total) required peritoneal dialysis. The cardiac pathology was transposition of great arteries in 133 cases, tetralogy of Fallot in 37, aorticopulmonary window associated with interrupted aortic arch in 4 and total anomalous pulmonary venous return in 5, and other complex pathology in 7 cases. Prolonged peritoneal dialysis was usually required in infants with low weight, with episodes of pulmonary hypertensive crisis (p < 0.05), and with preoperative renal dysfunction. No major complication was observed related to the peritoneal dialysis catheter. Of 186 patients, 23 (12.3%) had acute renal failure, and 4 of them died (2.15% of all patients underwent operation, 17.3% of those with acute renal failure). It has been demonstrated that the combination of peritoneal dialysis with perioperative ultrafiltration application was effective in providing the required postoperative negative fluid balance in especially complex congenital heart cases and affected survival positively.

Management of infants and young children with combined heart and kidney failure

Most infants and children referred for cardiac transplantation have low cardiac output with concurrent renal hypoperfusion leading to renal insufficiency and failure. This article is a review of the literature of and a single center's experience with combined heart and kidney failure in infants and children less than 10 yr of age. While 39 infants less than 10 yr of age were dialyzed pre- or peri-operatively, none required dialysis support at the time of discharge or in 5-10 yr follow-up. Based on our experience we recommend heart transplant alone in infants and young children with primary heart disease even though they have renal dysfunction.

Adequacy of peritoneal dialysis in children following cardiopulmonary bypass surgery

Acute renal failure requiring renal replacement therapy can complicate cardiopulmonary bypass in children. Peritoneal dialysis has been shown to stabilize electrolytes and improve fluid status in these patients. To assess dialysis adequacy in this setting, we prospectively measured Kt/V and creatinine clearance in five patients (6-839 days of age) requiring renal replacement therapy at our institution. Median dialysis creatinine clearance was 74.25 L/week/1.73m(2) (range 28.28-96.63 L/week/1.73m(2)). Residual renal function provided additional solute clearance as total creatinine clearance was 215.97 L/week/1.73m(2) (range 108.04-323.25 L/week/1.73m(2)). Dialysis Kt/V of >2.1 (median 4.84 [range 2.12-5.59]) was achieved in all patients. No dialysis-associated complications were observed. We conclude that peritoneal dialysis is a safe, simple method of providing adequate clearance in children who develop acute renal failure following exposure to cardiopulmonary bypass.