Bleeding in Critically Ill Children-Review of Literature, Knowledge Gaps, and Suggestions for Future Investigation

Clinically significant bleeding complicates up to 20% of admissions to the intensive care unit in adults and is associated with severe physiologic derangements, requirement for significant interventions and worse outcome. There is a paucity of published data on bleeding in critically ill children. In this manuscript, we will provide an overview of the epidemiology and characteristics of bleeding in critically ill children, address the association between bleeding and clinical outcomes, describe the current definitions of bleeding and their respective limitations, and finally provide an overview of current knowledge gaps and suggested areas for future research.

Risk of incident bleeding after acute kidney injury: A retrospective cohort study

PURPOSE

End-stage kidney disease (ESKD) causes bleeding diathesis; however, whether these findings are extrapolable to acute kidney injury (AKI) remains uncertain. We assessed whether AKI is associated with an increased risk of bleeding.

METHODS

Single-center retrospective cohort study, excluding readmissions, admissions <24 h, ESKD or kidney transplants. The primary outcome was the development of incident bleeding analyzed by multivariate time-dependent Cox models.

RESULTS

In 1001 patients, bleeding occurred in 48% of AKI and 57% of non-AKI patients (p = .007). To identify predictors of incident bleeding, we excluded patients who bled before ICU (n = 488). In bleeding-free patients (n = 513), we observed a trend toward higher risks of bleeding in AKI (22% vs. 16%, p = .06), and a higher risk of bleeding in AKI-requiring dialysis (38% vs. 17%, p = .01). Cirrhosis, AKI-requiring dialysis, anticoagulation, and coronary artery disease were associated with bleeding (HR 3.67, 95%CI:1.33-10.25; HR 2.82, 95%CI:1.26-6.32; HR 2.34, 95%CI:1.45-3.80; and HR 1.84, 95%CI:1.06-3.20, respectively), while SOFA score and sepsis had a protective association (HR 0.92 95%CI:0.84-0.99 and HR 0.55, 95%CI:0.34-0.91, respectively). Incident bleeding was not associated with mortality.

CONCLUSIONS

AKI-requiring dialysis was associated with incident bleeding, independent of anticoagulant administration. Studies are needed to better understand how AKI affects coagulation and clinical outcomes.

Dialysis-dependent acute kidney injury in children with end-stage liver disease: prevalence, dialysis modalities and outcome

BACKGROUND

Acute kidney injury (AKI) is a major complication in children with hepatic failure which leads to increased morbidity and mortality. The aim of this study was to provide paediatric data on the prevalence of dialysis-dependent AKI (dAKI), the feasibility and efficacy of dialysis methods and outcome.

METHODS

We conducted a retrospective analysis of 367 children listed for orthotopic liver transplantation (OLT) in our centre during the past decade.

RESULTS

Data on 30 children (15 boys, 15 girls) were compiled for retrospective analysis, and data on dialysis feasibility and efficacy were available for 26 of these. Median age was 3.5 (range 0.4-17.7) years. Median MELD (Model For End-Stage Liver Disease) score was 33. dAKI was caused by hepato-renal syndrome in 16 of the 30 children. Twenty-one patients were treated with continuous veno-venous haemofiltration (CVVH), and nine patients received peritoneal dialysis (PD). Overall mortality was 77%. Mortality within the PD-group was 100 % versus 67% in the CVVH-group (p = 0.039). Urea reduction rate within the first 24 h of treatment was 12.9% in the PD group and 23.5% in the CVVH group (p = 0.019).

CONCLUSIONS

Children with end-stage liver disease have a high risk for dAKI associated with high mortality. CVVH is associated with better efficacy and less mortality than PD.

Pediatric transplantation: managing bleeding

There has been extraordinary progress over the last half-century in the field of medical transplantation in which tissue, organs, or body parts from one human are placed into another. Solid organ transplants have allowed thousands of children with otherwise devastating inherited or acquired disorders to survive. Depending upon the clinical situation, there are many specific peri-transplant issues that must be carefully addressed to optimize outcomes. Although surgical, immunologic, and infectious concerns are usually in the forefront, important aspects regarding hemostasis frequently arise. The number of solid organs that can be successfully transplanted in children has expanded over the last decades and includes kidney, liver, heart, lung, intestine, pancreas, and thymus. Bleeding complications may occur in the setting of organ failure prior to transplantation, during the surgical procedure, or in the post-transplant setting, and can results in significant morbidity. This report will focus on preventing and managing non-surgical-related bleeding complications in children undergoing liver, heart, kidney transplantation, in whom there are often unique aspects of coagulation to be considered.

Regional citrate anticoagulation--a safe and effective procedure in pediatric apheresis therapy

Regional citrate anticoagulation (RCA) has been considered to be a standard component of pediatric apheresis therapy for more than a decade. However, data on dosing recommendations and evaluations of the effectiveness and safety of anticoagulation are rarely found in published reports. The aim of this retrospective analysis was to present our single-center experience with RCA in pediatric apheresis therapy with the aim of developing an operating procedure. Five children aged 7-14 years underwent a total of 72 (range 3-44) therapeutic apheresis sessions with RCA in the form of immunoadsorption therapy (2 patients), low-density lipoprotein (LDL)-apheresis (1 patient), and plasmapheresis (two patients). A 3% citrate solution was used. Citrate flow was started at 4.0% of the blood flow velocity and was adapted to match post-filter ionized calcium levels ≤ 0.30 mmol/l. Once the patient's ionized calcium fell to <1.05 mmol/l, an intravenous 10% calcium gluconate solution was administered. Twenty pediatric apheresis patients who received standard heparinization, matched for age, body surface area, processed plasma volume, and blood flow velocity, were enrolled in the study as a comparison group. No side effects were experienced in 72 apheresis session. The 3% citrate solution had to be reduced gradually during the apheresis session and was infused at a mean of 2.8-3.8% of the blood flow rate. Serum bicarbonate levels before and after the apheresis session with RCA [23.9 (range 18.9-30.1) vs. 26.3 (20.2-33.0) mmol/l, respectively] were significantly different (p=0.013). All patients required intravenous calcium substitution to maintain serum calcium levels within the physiological range. Due to the administration of the 3% citrate solution and calcium, all patients significantly gained weight during the procedure, with a median weight gain of 2.5% (p<0.001). The extra fluid load caused problems in patients with kidney failure. Our regimen with RCA is safe, feasible, and effective in pediatric therapeutic apheresis therapy. For RCA in apheresis, we recommend (1) a citrate (3%) flow of 3.3% of the blood flow, (2) prophylactic intravenous calcium substitution from the beginning, and (3) a more highly concentrated citrate solution in the case of oliguric patients.

Regional citrate anticoagulation is safe in intermittent high-flux haemodialysis treatment of children and adolescents with an increased risk of bleeding

BACKGROUND

Regional citrate anticoagulation (RCA) is strongly recommended for adults with an increased risk of bleeding complications. The objective of this retrospective analysis was to evaluate an RCA protocol concerning feasibility and safety in intermittent high-flux haemodialysis (iHD) treatment in children and adolescents.

METHODS

Eighteen children and adolescents aged 5-17 years (median 15 years) underwent 74 iHD treatment sessions with RCA. Twelve of 18 patients presented with overt local or diffuse haemorrhage before beginning the HD sessions, and six had an increased risk of haemorrhagic complications. Forty children on acute haemodialysis with general heparin anticoagulation, matched for bleeding risk, age and body surface area, served as a control group. Citrate 3% solution was begun with 3.3% blood flow rate, and calcium gluconate 10% substitution was started with 0.4% of blood flow rate. Citrate flow was adapted to achieve a post-filter ionized calcium of ≤0.30 mmol/L; calcium substitution was adapted to maintain the patients' serum calcium levels within the physiological range. Calcium-free dialysis fluid was used. The blood flow rate ranged from 3 to 5 mL per minute and kilogram body weight.

RESULTS

Regional anticoagulation was successfully achieved within the extracorporeal blood circuit, while the coagulation of all 18 patients remained within physiological parameters. No adverse effects of RCA were observed. In all 18 children, neither new haemorrhage nor worsening of the bleeding situation occurred, and in 10/12 patients, bleeding stopped during dialysis with RCA. In contrast, one-third of the control group developed new haemorrhagic complications or presented with worsening of pre-existing bleeding during haemodialysis (P = 0.006).

CONCLUSION

RCA is feasible, safe and effective in paediatric intermittent haemodialysis treatment.