Acute renal failure complicating pediatric cardiac surgery: a comparison of survivors and nonsurvivors following acute peritoneal dialysis

Peritoneal dialysis during congenital heart surgery admissions: insights from a large database

BACKGROUND

The management of fluid overload after congenital heart surgery has been limited to diuretics, fluid restriction, and dialysis. This study was conducted to determine the association between peritoneal dialysis and important clinical outcomes in children undergoing congenital heart surgery.

METHODS

A retrospective review was conducted to identify patients under 18 years of age who underwent congenital heart surgery. The data were obtained over a 16-year period (1997-2012) from the Kids' Inpatient Database. Data analysed consisted of demographics, diagnoses, type of congenital heart surgery, length of stay, cost of hospitalisation, and mortality. Logistic regression was performed to determine factors associated with peritoneal dialysis.

RESULTS

A total of 46,176 admissions after congenital heart surgery were included in the study. Of those, 181 (0.4%) utilised peritoneal dialysis. The mean age of the peritoneal dialysis group was 7.6 months compared to 39.6 months in those without peritoneal dialysis. The most common CHDs were atrial septal defect (37%), ventricular septal defect (32.6%), and hypoplastic left heart syndrome (18.8%). Univariate analyses demonstrated significantly greater length of stay, cost of admission, and mortality in those with peritoneal dialysis. Regression analyses demonstrated that peritoneal dialysis was independently associated with significant decrease in cost of admission (-$57,500) and significant increase in mortality (odds ratio 1.5).

CONCLUSIONS

Peritoneal dialysis appears to be used in specific patient subsets and is independently associated with decreased cost of stay, although it is associated with increased mortality. Further studies are needed to describe risks and benefit of peritoneal dialysis in this population.

Passive Peritoneal Drainage Impact on Fluid Balance and Inflammatory Mediators: A Randomized Pilot Study

BACKGROUND

Infants after cardiopulmonary bypass are exposed to increasing inflammatory mediator release and are at risk of developing fluid overload. The aim of this pilot study was to evaluate the impact of passive peritoneal drainage on achieving negative fluid balance and its ability to dispose of inflammatory cytokines.

METHODS

From September 2014 to November 2016, infants undergoing STAT category 3, 4, and 5 operations were randomized to receive or not receive intraoperative prophylactic peritoneal drain. We analyzed time to negative fluid balance and perioperative variables for each group. Pro- and anti-inflammatory cytokines were measured from serum and peritoneal fluid in the passive peritoneal drainage group and serum in the control group postoperatively.

RESULTS

Infants were randomized to prophylactic passive peritoneal drain group (n = 13) and control (n = 12). The groups were not significantly different in pre- and postoperative peak lactate levels, postoperative length of stay, and mortality. Peritoneal drain patients reached time to negative fluid balance at a median of 1.42 days (interquartile range [IQR]: 1.00-2.91), whereas the control at 3.08 (IQR: 1.67-3.88; P = .043). Peritoneal drain patients had lower diuretic index at 72 hours, median of 2.86 (IQR: 1.21-4.94) versus 6.27 (IQR: 4.75-11.11; P = .006). Consistently, tumor necrosis factor-α, interleukin (IL)-4, IL-6, IL-8, IL-10, and interferon-γ were present at higher levels in peritoneal fluid than serum at 24 and 72 hours. However, serum cytokine levels in peritoneal drain and control group, at 24 and 72 hours postoperatively, did not differ significantly.

CONCLUSIONS

The prophylactic passive peritoneal drain patients reached negative fluid balance earlier and used less diuretic in early postoperative period. The serum cytokine levels did not differ significantly between groups at 24 and 72 hours postoperatively. However, there was no significant difference in mortality and postoperative length of stay.

Peritoneal Dialysis in Pediatric Postoperative Cardiac Surgical Patients

Background

We determined the prevalence of acute kidney injury requiring peritoneal dialysis (PD), the factors associated with early PD initiation, prolonged PD and mortality among pediatric postoperative cardiac surgical patients.

Materials and Methods

The hospital records of 23 children, aged 12 years or younger, who had undergone cardiac surgery and required PD subsequently, during a 1-year period were reviewed. Demographic data, intraoperative variables, and postoperative complications were compared between survivors and nonsurvivors of PD, between the short and long duration PD groups, and between the early and late PD initiation groups.

Results

Six hundred and eight pediatric patients who underwent open heart surgery were enrolled in this study. 23 (3.78%) of them required PD. When compared with survivors (n = 11), non survivors (n =12) were more likely to have a higher serum procalcitonin (p = 0.01), higher serum potassium on day 2 (p = 0.001), day 3 (p = 0.04), day of termination of PD (p = 0.001) and a lower urine output on day 3 of PD (p = 0.03). Prolonged PD was associated with time of PD initiation (p = 0.01), a higher postoperative serum creatinine on day 3 (p = 0.01) of PD initiation as well on the day of PD termination (p = 0.01) and the final outcome in terms of survival (p = 0.02). Factors significantly associated with an early PD initiation were CPB time (p = 0.04), sepsis (p = 0.02) and shorter PD duration (p = 0.003).

Conclusion

PD is very useful mode of renal replacement therapy among pediatric postoperative cardiac surgical patients. The intraoperative and postoperative variables have important association with the time of PD initiation, PD duration and patient survival.

How to cite this article

Sahu MK, Bipin C, Arora Y, Singh SP, Devagouru V, Rajshekar P, et al. Peritoneal Dialysis in Pediatric Postoperative Cardiac Surgical Patients. Indian J Crit Care Med 2019;23(8):371-375.

Acute Kidney Injury Following Cardiac Surgery in Neonates and Young Infants: Experience of a Single Center Using Novel Perioperative Strategies

OBJECTIVE

Acute kidney injury (AKI) following cardiac surgery is a serious complication with a reported incidence of 30% to 50%. This study sought to determine the prevalence and risk factors for AKI among neonates and young infants undergoing repair of cardiac defects at an institution using novel perioperative strategies.

METHODS

A retrospective analysis of 102 consecutive infants (<2 months) undergoing repair of cardiac defects on cardiopulmonary bypass formed the study group. Cardiac diagnoses were stratified according to the Society of Thoracic Surgeons Congenital Heart Surgery (STAT) mortality categories. The prevalence of AKI within 72 hours was defined according to the three-stage Acute Kidney Injury Network criteria. Novel bypass strategies to preserve renal function included maintenance of higher hematocrit and high flow rates on cardiopulmonary bypass despite systemic hypothermia, and avoidance of albumin and milrinone in the perioperative period.

RESULTS

Mean age was 24 ± 19 days. Eighteen patients were less than 7 days of age at the time of surgery. Patient distribution according to STAT categories was as follows: 1 (n = 21), 2 (n = 12), 3 (n = 22), 4 (n = 28), and 5 (n = 19). The incidence of stages 1, 2, and 3 AKI in the population was 8% (n = 9), 2% (n = 2), and 0% (n = 0), respectively. On multivariate analysis higher STAT category was the only significant risk factor for AKI.

CONCLUSION

Current incidence of AKI following cardiac surgery in young infants at our institution is low. Novel perioperative strategies may have contributed to the low observed incidence of AKI in our patient population. Increased complexity of heart disease was a risk factor for AKI.

Cardiac intensive care for the neonate and child after cardiac surgery

PURPOSE OF REVIEW

The focus of postoperative care in the pediatric patient with congenital heart disease has become a reduction in length of stay and morbidity. This review will discuss strategies to achieve this goal and recent studies to support current practices.

RECENT FINDINGS

Most agree that prolongation of the length of stay following a cardiac surgery contributes to morbidity. Postoperative feeding difficulty, hyperglycemia, acute kidney injury, fluid overload, and prolonged intubation contribute significantly to length of stay.

SUMMARY

Postoperative care of the neonate and child following a cardiac surgery remains challenging with limited data to drive our practices. Patients remain at risk for significant morbidity, and future studies should focus on recognizing predictors of morbidity, prevention, and treatment.

A systematic review of acute kidney injury in pediatric allogeneic hematopoietic stem cell recipients

The process of allogeneic HSCT in children is associated with frequent AKI and mortality, but the epidemiology is not widely reported. The aim of this review was to summarize the available evidence on incidence, risk factors, timing, and prognosis of AKI in children following HSCT. We systematically reviewed all observational studies reporting incidence and outcomes of AKI in pediatric allogenic HSCT recipients. The minimum criteria for AKI were defined as an increase in sCr ≥ x1.5 or urine output ≤0.5 mL/kg/min over six h. Medline and Embase were searched until March 2014. From 993 electronic records, five were eligible for inclusion (n = 571 patients). The average incidence of AKI within the first 100 days following HSCT was 21.7% (range 11-42%), and the average time of onset was 4-6 wk post-transplant. Risk factors for AKI included cyclosporine toxicity, amphotericin B and foscarnet, SOS, and having a mismatched donor. There were conflicting reports on whether AKI was associated with the development of CKD. AKI is a common and potentially life-threatening complication following HSCT in children. Further quality observational studies are needed to accurately determine the epidemiology and prognosis of AKI in this population.

Use of a simply modified drainage catheter for peritoneal dialysis treatment of acute renal failure associated with cardiac surgery in infants

Acute renal failure (ARF) is a common complication in infants who undergo cardiac surgery in the intensive care unit. We report on a modified drainage catheter used in peritoneal dialysis (PD) for the treatment of ARF associated with cardiac surgery in infants. Thirty-nine infants with congenital heart disease undergoing cardiac surgery who developed ARF at our center between January 2009 and January 2012 were assessed. A modified drainage catheter for PD was used in these infants. Their demographic, clinical, and surgical data were analyzed. Thirty infants with ARF were cured by PD, and the other 9 died in the first 48 hours because of the severity of the acute cardiac dysfunction. All these infants were dependent upon mechanical ventilation during the postoperative period and used vasoactive drugs. In the survival group, the interval between the procedure and initiation of PD was 13.6 ± 6.5 (range, 6-30) hours. PD duration was 3.9 ± 0.9 (3-6) days. Minor complications were encountered in some patients (asymptomatic hypokalemia, hyperglycemia, and thrombocytopenia). These complications were readily treated by drugs or resolved spontaneously. Hemodynamics, cardiac function, and renal function improved significantly during PD. These data suggest that PD using a modified drainage catheter for ARF after cardiac surgery in infants is safe, feasible, inexpensive, and yields good results.

Prophylactic peritoneal dialysis catheter does not decrease time to achieve a negative fluid balance after the Norwood procedure: a randomized controlled trial

OBJECTIVE

Infants and children who undergo cardiopulmonary bypass and cardiac surgery are at risk of postoperative fluid overload. Peritoneal dialysis catheter (PDC) and peritoneal dialysis are reported to be effective means of postoperative fluid management. We sought to test the hypothesis that PDC insertion in the operating room at the time of Norwood palliation would decrease the time to achieve a negative fluid balance in a group of neonates with hypoplastic left heart syndrome.

METHODS

A single center randomized controlled trial was performed. We randomized neonates with hypoplastic left heart syndrome to prophylactic PDC, with or without dialysis, or standard care (ie, no PDC).

RESULTS

Twenty-two neonates were included; 10 were randomized to PDC and 12 were randomized to standard care. The mean time to first postoperative negative fluid balance was 2.70 ± 1.06 days for the prophylactic PDC group and 2.67 ± 0.65 days for the standard care group (P = .93). There was no difference between the 2 groups in time to lactate ≤ 2 mmol/L, maximum vasoactive-inotrope score on postoperative days 2 to 5, time to sternal closure, time to first extubation, modified clinical outcome score, or hospital length of stay. Twenty-one patients (95%) survived to hospital discharge. Four patients randomized to prophylactic PDC had 1 or more serious adverse events compared with no patients in the standard care group (P = .03).

CONCLUSIONS

Prophylactic PDC, with or without dialysis, did not decrease the time to achieve a negative fluid balance after the Norwood procedure, did not alter physiological variables postoperatively, and was associated with more severe adverse events.

Incidence, risk factors, and outcomes of acute kidney injury after pediatric cardiac surgery: a prospective multicenter study

OBJECTIVE

To determine the incidence, severity, and risk factors of acute kidney injury in children undergoing cardiac surgery for congenital heart defects.

DESIGN

Prospective observational multicenter cohort study.

SETTING

Three pediatric intensive care units at academic centers.

PATIENTS

Three hundred eleven children between the ages of 1 month and 18 yrs undergoing pediatric cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury was defined as a ≥50% increase in serum creatinine from the preoperative value. Secondary outcomes were length of mechanical ventilation, length of intensive care unit and hospital stays, acute dialysis, and in-hospital mortality. The cohort had an average age of 3.8 yrs and was 45% women and mostly white (82%). One-third had prior cardiothoracic surgery, 91% of the surgeries were elective, and almost all patients required cardiopulmonary bypass. Acute kidney injury occurred in 42% (130 patients) within 3 days after surgery. Children ≥2 yrs old and <13 yrs old had a 72% lower likelihood of acute kidney injury (adjusted odds ratio: 0.28, 95% confidence interval: 0.16, 0.48), and patients 13 yrs and older had 70% lower likelihood of acute kidney injury (adjusted odds ratio: 0.30, 95% confidence interval: 0.10, 0.88) compared to patients <2 yrs old. Longer cardiopulmonary bypass time was linearly and independently associated with acute kidney injury. The development of acute kidney injury was independently associated with prolonged ventilation and with increased length of hospital stay.

CONCLUSIONS

Acute kidney injury is common after pediatric cardiac surgery and is associated with prolonged mechanical ventilation and increased hospital stay. Cardiopulmonary bypass time and age were independently associated with acute kidney injury risk. Cardiopulmonary bypass time may be a marker for case complexity.

Congenital heart surgery in infants: effects of acute kidney injury on outcomes

OBJECTIVES

We sought to characterize factors and outcomes associated with postoperative acute kidney injury in infants undergoing cardiac surgery.

METHODS

We retrospectively studied 430 infants (<90 days) who underwent heart surgery for congenital defects. With a pediatric modified version of the Acute Kidney Injury Network classification, we performed statistical analyses to detect factors and outcomes associated with postoperative acute kidney injury.

RESULTS

Postoperative acute kidney injury occurred in 225 patients (52%): 135 patients (31%) reached maximum acute kidney injury stage I, 59 (14%) reached stage II, and 31 (7%) reached stage III. On multivariable analysis, single-ventricle status (odds ratio, 1.6; 95% confidence interval, 1.08-2.37; P = .02), cardiopulmonary bypass (odds ratio, 1.2; 95% confidence interval 1.01-1.47; P = .04), and higher reference serum creatinine (odds ratio, 5.1; 95% confidence interval, 1.94-13.2; P = .0009) were associated with postoperative acute kidney injury. Thirty-two (7%) patients died in the hospital. Multivariable logistic regression showed that more severe acute kidney injury was associated with in-hospital mortality (maximum acute kidney injury stage II odds ratio, 5.1; 95% confidence interval, 1.7-15.2; P = .004; maximum acute kidney injury stage III odds ratio, 9.46; 95% confidence interval, 2.91-30.7; P = .0002) and longer mechanical ventilation and inotropic support. All acute kidney injury stages were associated with longer intensive care durations. Stage III acute kidney injury was associated with systemic ventricular dysfunction at hospital discharge.

CONCLUSIONS

Perioperative acute kidney injury is common in infant heart surgery and portends a poor clinical outcome.

Use of peritoneal dialysis after surgery for congenital heart disease in children

Acute kidney injury (AKI) is a common complication in children after surgery for congenital heart disease, and peritoneal dialysis (PD) is usually the renal replacement therapy (RRT) of choice, especially in very young children. The aim of the present study was to describe our experience of using PD to treat AKI after cardiac surgery. We retrospectively analyzed children 1 week to 16 years of age undergoing cardiac surgery during 2000-2008 and found the incidence of AKI treated with PD to be 2.3%. In the 23 patients treated with PD (13 male; average age: 29 ± 48.4 months; weight: 9.1 ± 8.1 kg), the indications for PD initiation were oliguria (n = 13), anuria (n = 9), and acidosis (n = 1). The average time between cardiac surgery and AKI was 4.8 ± 16.8 hours, and between AKI and PD initiation, it was 12 ± 16.8 hours. Patients were treated for a mean of 4.8 ± 3.8 days. Two patients developed peritonitis, and mechanical dysfunction of the PD catheter occurred in 1 patient. In-hospital mortality was 43.4%. Patients treated with PD weighed less (p = 0.004) and had longer bypass time (p = 0.004), inotrope use (p = 0.000), and mechanical ventilation (p = 0.000). However, in a regression analysis, only cardiopulmonary bypass time (odds ratio: 1.021; 95% confidence interval: 0.998 to 1.027; p = 0.032) remained predictive of a subsequent need for PD. We conclude that PD is an efficacious RRT for AKI in children undergoing cardiac surgery and that, in this setting, bypass time is the strongest predictor of a subsequent need for RRT.

An update and review of acute kidney injury in pediatrics

OBJECTIVES

To inform the pediatric intensivist of recent advancements in acute kidney injury diagnosis and management.

DATA SOURCES

Studies were identified from MEDLINE (OVID), PubMed, and the Cochrane Library for topics relevant to acute kidney injury. We also reviewed bibliographies of relevant studies. DATA EXTRACTION, SYNTHESIS, AND OUTLINE REVIEW: Because of the lack of prospective trials, a majority of information is extracted from observational and retrospective data. The pathophysiology section reviews acute kidney injury mechanisms and highlights data regarding distal injury from experimental acute kidney injury. The epidemiology section focuses on incidence and outcomes of acute kidney injury, highlighting new strategies for diagnosis. The management section cites studies investigating hemodynamic optimization, nutrition, and fluid management, including the indications and impact of continuous renal replacement therapy in fluid overload.

CONCLUSIONS

There is limited data-driven evidence in pediatrics regarding effective therapy for acute kidney injury, a significant problem in the pediatric intensive care unit extending length of stay, ventilator days, and overall mortality. Sublethal kidney injury may be contributing to overall morbidity. We conclude that prospective clinical trials are needed to evaluate specific diagnostic aids, such as biomarkers, and therapeutic strategies, such as early initiation of continuous renal replacement therapy in children with fluid overload.

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.

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.

Hyperglycemia and the outcome of pediatric cardiac surgery patients requiring peritoneal dialysis

OBJECTIVE

To study the nature of the association between glycemia and ICU mortality in pediatric cardiac surgery patients treated with peritoneal dialysis (PD).

MATERIALS AND METHODS

Retrospective observational study in the ICU of a tertiary hospital involving forty pediatric cardiac surgery patients treated with PD. We selected patients requiring PD, extracted glucose measurements and nutritional intake data during ICU stay and calculated mean and maximum blood glucose values i) during ICU stay; ii) during dependence on PD; and iii) during independence from PD. We statistically assessed the relationship between glycemia-related variables and ICU mortality.

MEASUREMENTS AND RESULTS

Twenty-two patients treated with PD died (mortality 55%). In the PD cohort, 9725 blood glucose measurements were performed (every 3.3 hours on average). The mean glycemia during dependence on PD was significantly higher in non-survivors than survivors (p<0.0001), but not during independence from PD (p=0.49). The area under the receiver operator characteristic curve for the mean glycemia during dependence on PD was significantly greater than that obtained during independence from PD. Even after adjustment for severity of illness using multivariate logistic analysis, the mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.

CONCLUSIONS

A higher mean blood glucose concentration during PD, but not during PD-free periods was associated with greater ICU mortality. Mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.

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.

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.

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

BACKGROUND

We determined the risk factors for peritoneal dialysis (PD) in young children undergoing open heart surgery and, in those patients requiring PD, factors associated with prolonged PD and mortality.

METHODS

The clinical records of 182 children, aged 3 years or younger, who had undergone open heart surgery during a 2-year period were reviewed. Demographic data, preoperative risk factors, intraoperative variables, and postoperative complications were compared between patients requiring PD and those who did not, and between survivors and nonsurvivors of PD.

RESULTS

Of the 182 patients, 31 (17%) required PD. Patients requiring PD were lighter and more likely to have required preoperative ventilation; had undergone more complex surgery requiring longer bypass and circulatory arrest; and had experienced a pulmonary hypertensive crisis (p < 0.01). Logistic regression identified circulatory arrest (relative risk, 9.4; p = 0.002), cardiopulmonary bypass duration (relative risk, 1.02; p = 0.028), and low cardiac output syndrome (relative risk, 12.9; p < 0.0001) as significant determinants. Peritoneal dialysis was effective in achieving negative fluid balance, although serum urea and creatinine levels remained static. Prolonged PD was associated with younger age, higher preoperative serum creatinine, higher postoperative oxygen requirement, postoperative pulmonary hypertensive crisis, and low cardiac output syndrome (p < 0.05). When compared with survivors (n = 22), nonsurvivors (n = 9) were more likely to have had syndrome disorders and required preoperative ventilation and higher postoperative ventilatory settings (p < 0.05).

CONCLUSIONS

Risk factors for PD in young children undergoing open heart surgery are circulatory arrest, cardiopulmonary bypass duration, and low cardiac output syndrome. The preoperative and postoperative cardiopulmonary status has a significant bearing on PD duration and patient survival.

Overview of pediatric renal replacement therapy in acute renal failure

The disease spectrum leading to pediatric renal replacement therapy (RRT) provision has broadened over the last decade. In the 1980s, intrinsic renal disease and burns constituted the most common pediatric acute renal failure etiologies. More recent data demonstrate that pediatric acute renal failure (ARF) most often results from complications of other systemic diseases, resulting from advancements in congenital heart surgery, neonatal care, and bone marrow and solid organ transplantation. In addition, RRT modality preferences to treat critically ill children have shifted from peritoneal dialysis to continuous renal replacement therapy (CRRT) as a result of improvements in CRRT technologies. Currently, multicenter prospective outcome studies for critically ill children with ARF are sorely lacking. The aims of this article are to review the pediatric specific causes necessitating renal replacement therapy provision, with an emphasis on emerging practice patterns with respect to modality and the timing of treatment, and to focus upon the application of the different renal replacement therapy modalities and assessment of the outcome of children with ARF who receive renal replacement therapy.

Risk factors for long intensive care unit stay after cardiopulmonary bypass in children

OBJECTIVES

To determine whether children who experience longer intensive care unit (ICU) stays after open heart surgery may be identified at admission by clinical criteria. To identify factors associated with longer ICU stays that are potential targets for quality improvement.

SETTING

Tertiary pediatric cardiac surgical center.

DESIGN

A retrospective review was performed of pre-, intra-, and postoperative factors for children undergoing open heart surgery. All factors were evaluated for strength of association with length of ICU stay (LOS) using a negative binomial model. After multiple analysis, factors were deemed significant if associated with a LOS with p < .02.

PATIENTS

A total of 355 pediatric patients who had cardiac surgery with cardiopulmonary bypass in a 1-yr period from April 1999 until March 2000.

MEASUREMENTS AND MAIN RESULTS

Children who fell above the 95th percentile for LOS in our institution occupied 30% of bed days and had a three-fold greater mortality. Of all clinical factors considered, those significantly associated with LOS were as follows: preoperative--mechanical ventilation, neonatal status, medical problems, and transfer from abroad; intraoperative--higher operative complexity, increased cardiopulmonary bypass time or ischemic time, and circulatory arrest; and postoperative--delayed sternal closure, sepsis, renal failure, pulmonary hypertension, chylothorax, diaphragm paresis, and arrhythmia. A model combining all factors identified preoperative mechanical ventilation, neonatal status, major medical problems, operative complexity, cardiopulmonary bypass time, and a postoperative complication score as independently associated with LOS (p < .01).

CONCLUSIONS

At the time of ICU admission after open heart surgery, clinical criteria are evident that highlight a child's risk of longer ICU stay. These pre- and intraoperative factors relate to LOS independent of subsequent postoperative events. Those postoperative complications that are most strongly associated with increased LOS are identified and, therefore, made accessible to quality control.

Cardiopulmonary bypass in infants and children

Cardiopulmonary bypass (CPB) systems have evolved from futuristic visions of surgical pioneers to a safe and efficient tool in the therapy of treatment of cardiac disorders. There are many significant differences in the physiology between neonates and adult patients. There are currently very few congenital cardiac malformations that cannot be addressed effectively with surgical therapy. Yet, the necessity of CPB in the repair of these patients can still result in significant morbidity. A clearer understanding of the effects of CPB, hypothermia, and circulatory arrest is evolving and there is a considerable amount of research in these areas. It seems likely that modification of current CPB systems, minimization of exposure, and surgical techniques to avoid or limit the adverse effects may reduce mortality and morbidity in the future. The problems faced in these complex patients and procedures require that infant and neonatal cardiac surgery be performed in specialized centers with a multidisciplinary approach and specialized personnel. Future improvements in technology will likely result in improved long term outcome for children with congenital cardiac disease. Copyright 2000 by W.B. Saunders Company

Application of modified sequential organ failure assessment score in children after cardiac surgery

OBJECTIVE

To evaluate the usefulness of the modified sequential organ failure assessment (m/SOFA) score for assessing morbidity and mortality in pediatric patients after cardiac surgery.

DESIGN

Analysis of a prospectively collected database.

SETTING

Pediatric intensive care unit of a university-affiliated hospital.

PARTICIPANTS

Consecutive pediatric patients (n = 142) undergoing cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The m/SOFA score, consisting of 5 organ scores (maximum score of 20 points), was calculated on admission (initial) and at 12 and 36 hours postoperatively. An initial score of >5 points with an unchanged or upward postoperative trend predicted a higher postoperative mortality and a greater need for intensive care intervention. In neonates, sustained higher score >10 points predicted an outcome of death with a sensitivity of 100% and a specificity of 87%. Given the higher mortality related to immature organ function and a greater complexity of heart defects, the application of the m/SOFA score, a less invasive and simple way to assess organ damage, is especially suitable in neonates. The m/SOFA score would be more appropriately assessed according to the congenital heart defect or surgical procedure because the types of cardiac defect after the surgical repair affect each organ score measurement.

CONCLUSION

Application of the m/SOFA score in the early postoperative period, which reflects cumulative perioperative organ damage, would provide some direction to eventual outcomes of morbidity and mortality in patients with congenital heart defects undergoing surgery.

Etiology, prognosis, and outcome of post-operative acute renal failure

A Multivariate analysis was done in all patients who developed post operative ARF, during the period 1990-1995 to determine the etiological spectrum and to identify various variables affecting the outcome. Of 140 patients (110 operated at SGPGI and 30 operated outside) 116 underwent elective surgery. The different types of surgery leading to ARF were urosurgery (3.5%), open heart surgery (32.9%), gastrosurgery (16.4%), pancreatic surgery (9.3%), obstetrical surgery (3.6%) and others (2.8%). The incidence of ARF in SGPGI patients was highest in pancreatic surgery group (8.2%) followed by open heart surgery (3%). The different etiological factors responsible for ARF were perioperative hypotension (67.1%), sepsis (63.6%) and exposure to nephrotoxic drugs (29.3%). Sixty-four patients (45.7%) required dialysis. The overall mortality was 45%. The mortality was highest in patients who underwent open heart surgery (89.1%) followed by pancreatic surgery (84.6%). The factors associated with high mortality, other than the type of surgery, were preoperative hypotension (p < 0.05), oliguria (p < 0.01), need for dialysis (p < 0.05) and multiorgan failure (p < 0.001). AM following emergency surgery had poor outcome, though not statistically significant. Perioperative sepsis (p < 0.05) and preoperative use of aminoglycoside (p < 0.05) were significantly higher in patients operated outside SGPGI. This was associated with higher incidence of ARF. Thus we conclude that presence of multiorgan failure, oligoanuria, preoperative hypotension and need far dialysis are poor prognostic markers in ARF following surgery.

Peritoneal dialysis after infant open heart surgery: observations in 27 patients

BACKGROUND

The role of peritoneal dialysis (PD) in the management of infants after heart operation is under discussion. The aim of this study was to investigate the effect of PD on fluid balance and outcome.

METHODS

Twenty-seven (33%) of 81 consecutive infants who underwent heart operation required PD. In 22 patients (81%), PD was started prophylactically at the end of the operation. We recorded hemodynamic data and fluid balance. Patients experiencing acute renal failure (ARF) were compared with the remaining infants.

RESULTS

Eleven of 81 patients (14%) experienced ARF; 3 of them died (4% of all patients undergoing operation, 27% of those with ARF). Complications of PD, present in 33%, were transitory and of minor significance. Patients with ARF had decreased cardiac function compared with those without ARF but similar fluid balance.

CONCLUSIONS

Peritoneal dialysis is an effective and safe method for the treatment of ARF in infants after open heart operation. As PD is helpful in modulating postoperative fluid balance, prophylactic use of PD can be recommended for selected patients who are at risk for low cardiac output syndrome.

Dialysis support in the pediatric intensive care unit

Renal replacement therapy (RRT) in the pediatric intensive care unit encompasses a wide spectrum of dialysis modalities, including peritoneal dialysis, intermittent hemodialysis, and continuous hemodialysis. The choice RRT modality depends on the clinical setting, access, availability of equipment, and experience of the staff. Advances in newer access, dialysis equipment, and improved understanding of delivered dialysis have had a positive impact on survival in children with acute renal failure. Renal replacement therapy can also be used in children with specific clinical disease processes such as inborn errors of metabolism. Currently, there is no superior mode of RRT in acute renal failure. There are limited data available on the appropriate choice of modality for the specific disease state. This area requires further prospective studies to define the role of RRT in the pediatric intensive care unit.

Preoperative alpha2-adrenergic receptor agonists prevent the deterioration of renal function after cardiac surgery: results of a randomized, controlled trial

OBJECTIVE

To evaluate the influence of the alpha2-adrenergic receptor agonist clonidine on creatinine clearance as a measure of renal function.

DESIGN

Prospective, double-blind, randomized, placebo-controlled clinical trial.

SETTING

University hospital.

PATIENTS

Patients undergoing coronary artery bypass graft surgery (n = 48) with normal risk.

INTERVENTIONS

Administration of clonidine (4 micrograms/kg iv)) or placebo 1 hr before induction of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Induction and maintenance of anesthesia (etomidate, midazolam, and fentanyl) and cardiopulmonary bypass technique (nonpulsatile, normothermic, intermittent cold blood cardioplegia) were standardized in all patients. The night before surgery and the first and third night after surgery, creatinine clearance was calculated from a 12-hr urine collection period. Venous blood samples for determination of plasma antidiuretic hormone (ADH) concentrations were taken the evening before surgery, immediately before induction of anesthesia and the evening after surgery (n = 16). Arterial catecholamine plasma concentrations were determined (high-performance liquid chromatography) before induction, 15 mins after induction of anesthesia, immediately after sternotomy, before initiation of cardiopulmonary bypass, as well as 5, 15, and 30 mins after initiation of cardiopulmonary bypass (n = 16). The total amount of anesthetics, infusions, transfusions, diuresis, and blood loss was not different between the groups. Creatinine clearance decreased over the first postoperative night from 98 +/- 18 (preoperatively) to 68 +/- 19 mL/min (p < .05) in placebo-treated patients. Creatinine clearance remained unchanged in clonidine-treated patients (90 +/- 19 [preoperatively] to 92 +/- 17 mL/min). There was a significant difference in creatinine clearance between the groups during the first postoperative night (p < .05; Mann-Whitney U test). In the third postoperative night, mean creatinine clearance of both groups was not different (75 +/- 31 vs. 86 +/- 28 mL/min). ADH concentrations were not different between the groups at any time, while plasma catecholamine concentrations were always significantly lower in clonidine-treated patients.

CONCLUSIONS

Preoperative treatment with clonidine (4 microgram/kilogram) prevents the deterioration of renal function after cardiac surgery. This effect might be due to clonidine-induced reduction in the sympathetic nervous system response to coronary artery bypass graft surgery.

Renal replacement therapy after repair of congenital heart disease in children. A comparison of hemofiltration and peritoneal dialysis

The development of renal failure necessitating peritoneal dialysis after cardiac operations is associated with a reported mortality greater than 50%. Improved fluid removal and nutritional support have been reported with the use of continuous arteriovenous hemofiltration and continuous venovenous hemofiltration techniques. We have compared our experience with all three techniques in managing children who required renal replacement therapy after cardiac operations in terms of efficacy (fluid removal, calorie intake, and clearance of urea and creatinine), complications, and outcome. Over a 5-year period renal replacement therapy was initiated in 42 children, and in 34 of them it was successfully established for more than a 24-hour period: 17 were managed with peritoneal dialysis, 8 with continuous arteriovenous hemofiltration, and 9 with continuous venovenous hemofiltration. A net negative fluid balance was achieved in only 6 (35%) patients treated with peritoneal dialysis compared with 50% of those treated with continuous venovenous hemofiltration and 89% of those treated with continuous venovenous hemofiltration. In terms of nutritional support, calorie intake increased by 43% after peritoneal dialysis was started compared with 515% and 409% in the arteriovenous and venovenous hemofiltration groups, respectively, (p < 0.005). The serum urea levels fell by 36% (p = 0.02) and 39% (p = 0.005) compared with pre-therapy levels with arteriovenous and venovenous hemofiltration, respectively, and the creatinine content was reduced by 19% and 33% (p = 0.003). Neither parameter was reduced in the peritoneal dialysis group. We conclude that the use of hemofiltration as a renal replacement therapy after surgical correction of congenital heart disease offers significant advantages over the more traditional approach of peritoneal dialysis. In addition, we suggest that a more aggressive approach to the management of fluid overload and nutritional depletion with hemofiltration may result in a decrease in the very high mortality seen in renal failure after cardiac operations.