RESULTS

Demographics and clinical manifestations of the patients treated with CRRT are presented in Table 1. Of all children requiring CRRT, 58.8% were males. There were 55 patients (18.9%) aged less than 1 year, and 10% were aged less than 6 months. Fifty-five children (18.9%) weighed less than 10 kg, and 191 children (65.6%) weighed less than 30 kg. The mean age was 6.6 years (range 1.1 - 12.1 years) and the mean body weight was 23.2 kg (range 5.9– 40.5 kg).

Fifty-five patients received inotropic agents at CRRT initiation, and 30 of these patients required more than three kinds of inotropics. The mean duration in the ICU before CRRT initiation was 13.08 ± 5.86 hours.

Table 1. Characteristics of patients receiving CRRT

Variables Total number of patients (n=291)

Number of patients (%)

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Vasopressors at CRRT initiation

0 85(29.2%) CRRT: Continuous renal replacement therapy, ICU: intensive care unit

The details of the CRRT are shown in Table 2. Eighty-one patients received a combination of diffusion and convection (CVVHDF), 63 patients received the diffusion only CRRT modality (CVVHD), and only one patient received a convective modality (CVVH). In all 156 (55.9%) patients were initiated on CRRT without anticoagulants. Seventy-two (25.8%) patients were initiated on CRRT with a single infusion of nafamostat mesilate and 35 (12.5%) patients received a single dose of heparin. Twelve (4.3%) patients were switched from heparin to nafamostat mesilate and 4 (1.4%) patients were switched from nafamostat mesilate to heparin. The most common site of insertion of the initial hemo-catheter was left femoral (33.0%) and right femoral vein (31.9%), respectively. Twenty-one patients (7.8%) received extracorporeal membrane oxygenation (ECMO) and CRRT simultaneously. In such cases, the CRRT pump was cannulated into the ECMO circuit. The mean blood flow rate was 72.65±30.89 ml/min and the median PRISM III score was 5. The overall survival rate was 31.2 %. PRISMA^® (80.8%) was the most commonly used equipment for CRRT (Table 3).

The indications for initiating CRRT are listed in Table 4. The most common indications for CRRT were a combination of fluid overload and uremia with

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oliguria (60%), isolated oliguria refractory to diuretic treatment (46%), and isolated uremia (12.0%). Metabolic acidosis (7.6%) and isolated electrolyte imbalance (3.8%) were also marked as the cause for initiating CRRT in children.

Table 2. Technical characteristics of CRRT

Characteristics Total number of patients (n=291) Number of patients (%)

No anticoagulation 156(55.9%)

Heparin 35(12.5%)

Right internal jugular 31(11.5%)

Left internal jugular 22(8.1%)

CRRT: Continuous renal replacement therapy, CVVH: Continuous Veno-Venous Hemofiltration, CVVHD: Continuous veno-venous hemodialysis, CVVHDF: Continuous veno-venous hemodiafiltration

PCPS: percutaneous cardiopulmonary support, ECMO: Extracorporeal membrane oxygenation, PRISM: The Pediatric Risk of Mortality

Table 3. Distribution of CRRT machines which used to patients

CRRT machines Total number of patients (n=291) Number of patients (%)

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The presumptive diagnoses of patients who received CRRT were renal disease (e.g. focal segmental glomerulosclerosis (FSGS), nephrotic syndrome and hemolytic uremic syndrome (HUS), pure sepsis and drug intoxication-. 86.4% of the renal disease patients and 100% of the patients with drug intoxication survived after CRRT. Although malignancy was the most common underlying disease (116 patients, 39.9%), only 19.0% survived following CRRT treatment (Table 5).

Table 6 shows a comparison of the variables between survivors and non-survivors after CRRT. There was no difference in the age, weight, duration of CRRT, blood flow rate, and urine output. However, the mortality was higher in males than in females (P= 0.028). Mortality was also higher in children who required inotropic agents, diuretics, and anticoagulation agents compared to those who did not require these therapies (P<0.001, 0.025 and 0.013, respectively). In addition, the non-survivors group had a statistically significant higher %FO than the survivors’ group (P=0.041).

Table 4. Principal diagnosis and survival of CRRT patients

Indication Total number of patients (n=291)

Number of patients (%)

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Table 5. Indications for CRRT initiation

Parameter Numbers (n) Survivors (n) Survival (%)

Pure sepsis 15 5 33.3

CRRT: Continuous renal replacement therapy, FSGS: focal segmental glomerulosclerosis, HUSP:

hemolytic uremic syndrome

Table 6. Comparison of variables in patients comparison of variables between the survivors and non-survivors groups in patients receiving CRRT

Time until CRRT initiated† ± SD (hours)

4.4±8.4 2.8±3.9 0.256

Duration of CRRT ± SD (days) 8.1 ± 9.3 6.3 ± 7.3 0.095 Blood flow rate (ml/min) 70.3±30.0 74.4±31.7 0.298 Use of inotropics 50 (53.7%) 152 (76.8%) <0.001

12 Pediatric Risk of Mortality, SD: Standard deviation

†Hours from admitting intensive care unit (ICU) to CRRT initiation

Table 7 demonstrates a comparison of the laboratory variables between the survivors and non-survivors following CRRT. There were statistically significant differences between the groups in platelet counts, BUN, and creatinine level.

Other parameters including eGFR had no significant difference.

Multiple logistic regression analyses showed that sex, platelet count, and creatinine were predictive for the need of CRRT, survival or anything else (odds ratio [OR]: 2.074, 95% CI: 1

.

0.945-0.985

,

Kaplan-Meier survival curves for patients treated with CRRT indicate that there was no statistically significant difference in the combined cumulative survival of patients receiving diuretics in comparison to those who did not (P=0.760).

However, patients receiving inotropics and anticoagulation agents showed an increased cumulative survival compared to patients who did not receive these agents (P=0.010, P=0.046, respectively). (Figure 2).

Table 7. Comparison of laboratory results between survivors and non-survivors among patients who received CRRT

Parameter Survivors (n=93) Non-survivors

(n=198)

P value

Complete blood count

WBC (/mm3) 13163.41 ± 11733.89 9585.59 ± 10826.74 0.015

Hemoglobin (g/L) 9.65 ± 2.70 9.87±2.78 0.538

Hematocrit (%) 28.92±8.03 29.63±8.90 0.531

Platelet count (x10³/µL) 256.66±186.57 138.40±146.30 <0.001 Coagulation tests

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Prothrombin Time (sec) 24.81±30.76 24.60±26.33 0.955

aPTT (sec) 57.48±45.72 58.57±44.74 0.856

Glucose (mg/dL) 129.39±83.01 152.85±99.37 0.062

Potassium (mg/dL) 4.35±1.12 4.14±1.24 0.178

tCO2 (mg/dL) 18.72±7.22 19.75±7.22 0.277

BUN(mg/dL) 40.21±44.46 26.14±26.87 0.008

Creatinine (mg/dL) 2.50±3.86 1.03±1.13 0.001

eGFR (mL/min/1.73 m²) 83.56±60.25 77.85±46.12 0.670 WBC: white blood cell, aPTT:activated Partial Thromboplastin Time, ABGA: arterial blood gas analysis, pH: acidity, pCO2: partial pressure of carbon dioxide, pO2: partial pressure of oxygen, tCO2: total carbon dioxide, BUN: blood urea nitrogen, eGFR: estimated glomerular filtration rate

Table 8. Multiple logistic regression analysis of the risk for mortality in CRRT receiving patients

Variables

Mortality

OR (95% CI) P-value

Sex 2.074 (1.132-3.799) 0.018

Use of inotropics 0.545 (0.283-1.050) 0.070 Use of diuretics 0.891 (0.431-1.841) 0.755 Use of anticoagulation 1.646 (0.712-3.803) 0.244

%FO at CRRT 1.030 (0.985-1.077) 0.193

WBC 0.998 (0.969-1.028) 0.910

Platelet count 0.965 (0.945-0.985) 0.001

BUN 1.004 (0.991-1.017) 0.557

Creatinine 1.003 (0.870-1.156) 0.036

CRRT: Continuous renal replacement therapy, %FO: percent of fluid overload, WBC: white blood cell, BUN: blood urea nitrogen, OR: odds ratio, CI: confidence interval

14 (A)

(B)

15 (C)

Figure 2. Kaplan-Meier survival curves for patients receiving CRRT (A) Survival comparison depending on sexes (B) Survival comparison between anticoagulation used group and not-used group (C) Survival comparison between diuretics used group and not-used group