Navigating the therapeutic tightrope: Precision use of plasmapheresis and continuous renal replacement therapy in liver failure

Table 8 Consolidated summary of differentiation between use of therapeutic plasma exchange, continuous renal replacement therapy and therapeutic plasma exchange + continuous renal replacement therapy in acute liver failure and acute-on-chronic liver failure

Aspect	TPE	CRRT	TPE + CRRT
Mechanism	Removes/replaces plasma; clears protein-bound toxins (> 15000 Da), cytokines, DAMPs/PAMPs (e.g., bilirubin, bile acids, HMGB1, LPS) via centrifugal (80% efficiency) or membrane filtration[15]	Convection/diffusion; clears water-soluble toxins (< 15000 Da), ammonia, urea, electrolytes, small cytokines (IL-6, IL-8) via CVVH/CVVH/CVVHDF[19,82]	Sequential TPE targets large/protein-bound toxins + CRRT for small solutes/ammonia; sequential avoids overload (TPE first for inflammation, then CRRT for AKI). Combined via integrated circuits (e.g., PrismaFlex) for rapid multi-toxin clearance[73,75]
Indications	ALF: Severe inflammation (IL-6 >100 pg/mL); coagulopathy (INR > 1.5), HE (grades III-IV), toxin-driven ALF (acetaminophen, viral), Wilson’s autoimmune ALF[16,18,32,33]. ACLF: Bilirubin > 20 mg/dL) or HE (grades II-IV), or systemic inflammation (MELD score > 20). HBV-ACLF flares. Severe alcoholic hepatitis refractory to corticosteroids[12,13,40]	ALF: Early in AKI, progressive or hyperammonemia or advanced grades of HE or electrolyte disturbances or volume management when needed[54-58]. ACLF: Stage 3 AKI with progression or non-response to vasoconstrictors within 12-24 hours[67]	ALF: Fulminant cases with cerebral oedema + AKI (e.g., post-TPE hyperammonemia rebound)[75-79]. ACLF: ACLF-3 with combined hyperbilirubinemia (> 20 mg/dL) + AKI-3 + ammonia > 200 μmol/L; septic shock (SOFA > 12)[42,75,80,81]
Preferred types	Centrifugal (e.g., SpectraOptia; low flow 50-150 mL/minute for instability); HV-TPE (8-12 L, ALF); SV-TPE (2-4.5 L, ACLF/ALF); DPMAS add-on for HBV[15,18,34]	CVVHDF (dual, 35-70 mL/kg/hour); CVVH (ammonia focus, 35-50 mL/kg/hour); high-volume for severe ALF; RCA (3-4 mmol/L) anticoagulation[19,82]	Sequential: TPE (1-3 sessions) → CRRT (within 12 hours post-TPE for preemptive ammonia control); combined: Integrated (TPE 2000 filter on PrismaFlex, post-oxygenator in ECLS). Preferred in low-resource ICUs for sequential[27,63,75]
Pros	Rapid large-toxin clearance (bilirubin 30%-40% reduction); protein replenishment (INR drop 20%-50%); immunomodulation (IL-6/TNF-αdecreasing 20%-40%); survival increasing 10%-15% ALF, 5%-10% ACLF; bridge to transplant (eligibility increasing 15%)[16,18,34,38,40,45]	Ammonia clearance 40%-75% in 24-48 hours; hemodynamic stability (ICP decreasing 15-20 mmHg); AKI/fluid management (sepsis risk decreasing 15%); mortality RR: 0.65 ALF, 5%-10% survival increasing ACLF[64,65,71-73,82]	Ammonia decreasing 60%-80% + bilirubin decreasing 40%-60% (48 hours); fastest MOF reversal (SOFA decreasing 3-5 points in 72 hours); survival increasing 15%-25% vs monotherapy in ACLF-3; better bridge to LT (increasing 30% eligibility); reduced vasopressor needs (norepinephrine decreasing 20%-30% in sequence)[62,72,75,76]
Cons	Bleeding (5%-10%), infections (5%-15%), hypocalcemia (1.5%-9%), allergic reactions (2%-5%); hemodynamic instability (membrane type); high cost ($5-10K/session); limited access (20%-40% low-resource centres)[16,18,34,38,40,45]	Bleeding (22%), infections (15%), citrate toxicity (12%); slower for protein-bound toxins; circuit clotting (10%-20%); rebound ammonia risk (SLED 10%-15%)[64,65,71-73,82]	Fluid load increasing 10%-15% (combined), citrate accumulation increasing 12% (liver impairment), complexity/cost increasing 50%; hemodynamic dips (MAP decreasing 5-10 mmHg in 10% combined); infection increasing 8% if prolonged (> 7 days). Sequential mitigates (complications decreasing 5%-10%)[62,72,75,76]
Monitoring	Daily: INR, bilirubin, ammonia, cytokines (IL-6/TNF-α), neuro status (West Haven); biomarkers (NGAL for AKI); adjust per MELD/HE trends[16,18,34,38,40,45]	q4-6 hours: Ammonia, electrolytes, Ca2+ circuit pressures; NGAL/IL-6 for progression; hemodynamics/fluid balance[71-73]	Hybrid model: TPE: Same as TPE column + hourly ionised Ca2+, CRRT (or simultaneous): Same as the CRRT column, additional daily: Total bilirubin, INR, ammonia, lactate, SOFA/CLIF-SOFA citrate monitoring intensified: Post-filter iCa 0.25-0.35 mmol/L, systemic iCa 1.0-1.3 mmol/L, total/iCa ratio < 2.5; q12 hours neuro checks if HE present, NGAL/cystatin C q24 hours for early AKI recovery[62,72,75-77]
Survival benefit	ALF: Improve TFS by 10%-25% at 21-90 days compared with standard medical therapy alone[16,17,18,34]. Swaroop et al[38] in 2026 pilot RCT in ALF: No overall 30-day survival benefit (65% mortality in both arms, P = 1.0). ACLF: Significant reduction in mortality at 30 days (RR: 0.70; 95%CI: 0.60-0.81; P < 0.001) and at 90 days (RR: 0.81; 95%CI: 0.77-0.86; P < 0.001)[40]. Six studies (1495 patients; 2 RCTs) with data for 1-year survival showed better outcomes in the PLEX group (RR: 0.85; 95%CI: 0.79-0.92; P < 0.0001) compared to SMT[40]	ALF: A single systematic review to date shows: CRRT improve TFS (RR: 0.73, 95%CI: 0.57-0.94, P = 001, I2 = 54.74%)[64] may improve overall survival (RR: 0.83, 95%CI: 0.73-0.93, P < 0.001, I2 = 18.77%)[64]. However, most studies are limited by serious confounding and overall bias[64]. ACLF: 90-day TFS ranges from 6% to 23%; hospital mortality: 80%-90%. Non-transplant patients exhibit mortality of 90%-94% with intervention[71-74]	ALF: TPE + CRRT (mostly sequential/tandem) markedly improves transplant-free survival in pediatric ALF (44%-83%) vs single modality (approximately 30%-60%), with rapid ammonia clearance and HE resolution. In adults, however, adding TPE to CRRT shows no benefit and may even worsen outcomes post-transplant[62,75-79]. ACLF: Modest short-term survival gain (48%-65% at 28-90 days) over single therapy, mainly in HBV-related ACLF, with better MELD/SOFA reduction and sepsis control. In non-HBV and general ACLF-AKI cohorts, combined therapy is equivalent or inferior to TPE or CRRT alone, providing no consistent added survival advantage[42,72,75,80,81]

TPE: Therapeutic plasma exchange; CRRT: Continuous renal replacement therapy; DAMPs: Damage-associated molecular patterns; PAMPs: Pathogen-associated molecular patterns; HMGB1: High-mobility group box 1; LPS: Lipopolysaccharide; IL-6: Interleukin-6; CVVH: Continuous veno-venous hemofiltration; CVVHD: Continuous veno-venous hemodialysis; AKI: Acute kidney injury; ALF: Acute liver failure; INR: International normalized ratio; HE: Hepatic encephalopathy; ACLF: Acute-on-chronic liver failure; MELD: Model for end-stage liver disease; HBV: Hepatitis B virus; SOFA: Sequential organ failure assessment; HV-TPE: High-volume therapeutic plasma exchange; SV-TPE: Standard-volume therapeutic plasma exchange; DPMAS: Double plasma molecular adsorption system; RCA: Regional citrate anticoagulation; ECLS: Extracorporeal life support; ICU: Intensive care unit; TNF-α: Tumour necrosis factor-alpha; ICP: Intracranial pressure; RR: Risk ratio; MOF: Multiorgan failure; LT: Liver transplantation; SLED: Sustained low-efficiency dialysis; MAP: Mean arterial pressure; NGAL: Neutrophil gelatinase-associated lipocalin; CLIF: Chronic liver failure; iCa: Ionized calcium; TFS: Transplant-free survival; RCT: Randomised controlled trial; CI: Confidence interval; PLEX: Plasma exchange.