To Evaluate the Safety and Efficacy of Preemptive Administration of Continuous Renal Replacement Therapy in Patients With Acute Liver Failure With Cerebral Edema

Hypothesis: Investigator hypothesize that preemptive administration of continuous renal replacement therapy would be synergistic to plasma-exchange in ameliorating the cytokine storm, cerebral edema and improve outcomes in patients with non-acetaminophen ALF with cerebral edema compared to late initiation.

Aim and Objective -

AIM:

Primary

1. 21-day transplant free survival with Prometheus Secondary
2. To compare the improvement effect in cerebral edema and hepatic encephalopathy in both groups
3. To study the safety of therapy (incidence of intradialytic hypotension, impairment of coagulation, hypothermia)
4. Duration of mechanical ventilation and ICU stay in both groups
5. Impact on arterial lactate
6. Improvement in SIRS
7. Effect on systemic hemodynamics and pulmonary function
8. Effect on endotoxin, DAMPS, pro-inflammatory cytokines, endothelial functions and coagulation

Methodology Study Protocol

All patients will be evaluated as follows:

• Clinical history and examination
• Etiology of acute event
• Severity assessment indices
• Complications if any Investigations Arterial blood gas analysis
• Hematology
• CBC, Prothrombin time and INR
• Peripheral smear, Retics
• Thromboelastogram(ROTEM)
• S.Fibrinogen level
• Biochemistry
• Liver function testing
• Kidney function test
• Arterial ammonia levels
• Serum lactate
• CRP and procalcitonin
• S.Ferritin and LDH
• Etiology of acute event:
• Infectious etiology: IgM anti HAV, IgM anti HEV, IgM anti HBc ( If HBsAg +ve), IgM anti HDV ( If HBsAg +ve) , total antiHBc, anti HCV
• Non Infectious etiology: Alcohol binging in last 4 weeks, hepatotoxic drugs, ANA (>1: 80), IgG
• Non infectious etiology: Autoimmune markers, copper studies, iron studies, HOMA IR, FBS Imaging USG abdomen with Doppler for spleno-portal axis NCCT abdomen and brain Assessment of cerebral edema

1. Optic nerve sheath diameter
2. Transcranial doppler
3. Electroechocardiogram

Study Population: 60 patients with ALF will be randomized to two groups in 1:1 ratio.

Study Design:

• A randomized controlled study.
• The study will be conducted on patients admitted to Department of Hepatology from May 2021 to March 2023 at ILBS, New Delhi
• Study group will comprise of patients with acute liver failure (ALF) with documented cerebral edema on CT-scan and arterial ammonia >150 ug/dl Study Period: May 2021 to March 2023 Sample Size calculation: Currently there are lack of studies investigating the timing of CRRT in patients with ALF therefore a minimum of 60 patients 30 in each group would be included in the current study.

The detailed cytokine profile, endotoxin assay, markers of endothelial dysfunction and bioenergetics would be performed in a subset of 10 patients in each group.

Intervention: Continuous renal replacement therapy

Monitoring and Assessment: Hourly till the patient is in the intensive care unit then every 7 days for 1 month

Statistical analysis

• All variables shall be expressed in median (range)
• Variables will be compared by Mann- Whitney U test
• For Categorical variables - Chi-Square or Fisher's test
• Survival analysis will be done using cox-proportional regression analysis
• Actuarial probability of survival shall be calculated by Kaplan- Meier graph and compared by log- rank test.

Standard medical treatment: All patients will undergo plain CT-scan of the brain to screen for the presence and severity of cerebral edema in the emergency before being shifted to the L-ICU. In the L- ICU, patients will be managed by a multidisciplinary team. Intubation and ventilation will be undertaken for standard indications in addition to the development of grade 3 encephalopathy or evidence of cerebral edema on CT-scan. Ventilation will be managed by fentanyl and propofol along with the use of atracurium for paralysis wherever required. All patients will be monitored constantly for macro-hemodynamics, global tissue perfusion, and microcirculation. The macro-hemodynamic parameters included continuous monitoring of mean arterial pressure (MAP), heart rate and urine output per hour. The real-time monitoring of systemic vascular resistance (SVR), stroke volume variation (SVV), cardiac index (CI) and cardiac output (CO) will be done by a hemodynamic monitor (FloTrac™ system 4.0, Edwards Lifesciences, California, US) wherever feasible. Global tissue perfusion adequacy and indirect assessment of microcirculation will be done by measurement of arterial lactate. Fluid management will be done with crystalloids, with the use of colloids (5% albumin) in patients with severe hypoalbuminemia (serum albumin less than 2.5gm/dl). Norepinephrine will be the primary vasopressor used to target a mean arterial pressure of 65-70 mm of Hg. with adjunctive use of intravenous low dose hydrocortisone and vasopressin in patients not responsive to initial therapy.

Cerebral edema: The monitoring of cerebral edema will be performed measuring the optic nerve sheath diameter (ONSD) in both the eyes using a 7.5 MHz probe every 6-8 hours. Apart from this, routine monitoring of pupillary size and reactions, extensor posturing and plantar reflexes will be performed every 6-8 hrs. Transcranial doppler would be done every 6-8 hours. Patients will receive 3% hypertonic saline as a continuous infusion, initially started at 25ml /hr and titrated 6 hourly to between 5 and 20 mL per hour (maximum 100 ml/hour) to achieve serum sodium levels between 145-150 mmol/L. Intravenous 20% mannitol (1 g/kg IV bolus) over 20 to 30 minutes will be administered to those without renal failure. All patients will in addition receive intravenous N-acetylcysteine for 5 day.Routine electroencephalogram (EEG) will be done for all patients daily to screen for non-convulsive seizures which will be managed by intravenous levetiracetam. Assessment of coagulation will be performed by ROTEM at baseline and subsequently as required.

Protocol for standard-volume plasma-exchange

1. Standard-Volume Plasma Exchange: SVPE procedures will be performed using either Spectra Optia (SPO, Terumo BCT, Lakewood, CO, USA) continuous-flow centrifugal apheresis system or Haemonetics MCS+ (Braintree, MA, USA) intermittent flow centrifugal apheresis system via a double-lumen central venous dialysis catheter. All patients will receive plasma-exchange within first 6 hours of admission to the L-ICU along with a target volume of 1.5 to 2.0 plasma volumes per session. The replacement fluid used will be 90% FFP and 10% normal saline.PE will be performed on consecutive days until the desired response is achieved. [using investigator previously published protocol].
2. The number of sessions of SVPE in each patient will be decided based on the clinical response to SVPE. Dynamic assessment of the clinical parameters (signs of CE as assessed by pupillary size, reaction, and optic nerve-sheath diameter), INR, lactate and arterial ammonia will be performed at after each TPE. In patients with an improvement in INR, and signs of CE along with a reduction in ammonia at 6 hours which was sustained at 12 and 24 hours post-SVPE, subsequent sessions will be discontinued. PE will also be discontinued in patients who would show worsening in either clinical and/ or biochemical parameters. In patients who will develop adverse events, the PE procedure will be resumed or discontinued depending on the severity of adverse event and its resolution.

Randomization will be done by taking 1:1 ratio by computer-generated sealed envelopes by the clinical trial co-ordinator Group 1-Preemptive CRRT: In patients randomized to early CRRT, CRRT would be initiated within 12 hours of randomization.

Group 2: SMT - In patients randomized to SMT group, CRRT would be initiated as per the existing standard protocol.

in patients with worsening hyperammonemia despite two sessions of plasma-exchange patients meeting renal indications (hyperkalemia, volume overload, oliguria or metabolic acidosis etc).

The time to initiation of CRRT would be recorded in both groups after randomization.

Continuous renal replacement therapy will be administered as continuous venovenous hemodiafiltration (CVVHDF) using Prisma and Prismaflex (Gambro) devices, with blood flows ranging from 150-180 mL/hr and target effluent rates of 20 - 25 mL/kg/hr. Anticoagulation was not used during dialysis. CRRT would be continued until resolution of cerebral edema and in decrease in ammonia levels below 150 ug/dl or in those who develop adverse effects of therapy.