Acute liver failure secondary to yellow phosphorus rodenticide poisoning: Outcomes at a center with dedicated liver intensive care and transplant unit

Assessing the clinical efficacy of low-volume therapeutic plasma exchange in achieving recovery from acute liver failure induced by yellow phosphorous poisoning

BACKGROUND

Acute liver failure (ALF) following yellow phosphorous (YP) ingestion is similar to acetaminophen-induced ALF and it has become a public concern in our region. This study assessed low volume therapeutic plasma exchange (LV-TPE) efficacy in improving the transplant free survival in YP poisoning.

METHODS

Adult patients with toxicology reports of YP and ALF requiring critical care were included in the study. LV-TPE was planned for three consecutive days and three more if required. Performed 1.3 to 1.5 plasma volume replacing with 0.9% normal saline, 5% human albumin solution, and fresh frozen plasma based on ASFA 2019 criteria. MELD score, laboratory parameters, LV-TPE details were captured. The study end point was clinical outcome of the patients.

RESULTS

Among 36 patients, 19 underwent LV-TPE and 17 opted out of LV-TPE and they were included as a control arm. The MELD score was 32.64 ± 8.05 and 37.83 ± 9.37 in both groups. There were 13 survivors in LV-TPE group leading to a 68.42% reduction in mortality. The coagulation and biochemical parameters showed a significant percentage change after LV-TPE. Refractory shock, delay in initiating procedure and acidosis were independent predictors of mortality.

CONCLUSION

A well-timed LV-TPE improves the survival of patients with ALF due to YP poisoning.

Standard-Volume Is As Effective As High-Volume Plasma Exchange for Patients With Acute Liver Failure

Background/Aims

Acute liver failure (ALF) is associated with fatal outcomes without liver transplantation. Two randomized studies reported standard volume (SV) and high volume (HV) plasma exchange (PLEX) as effective therapeutic modalities for patients with ALF. However, no studies have compared the safety and efficacy of SV with HV PLEX, which we aimed to assess.

Methods

This retrospective study included patients with ALF admitted between March 2021 and March 2023 who underwent PLEX. All patients underwent HV PLEX until May 2022, and then thereafter, SV PLEX was performed. The objectives of the study were to compare transplant-free survival (TFS) at 30 days, efficacy in reducing severity scores, biochemical variables, and adverse events between SV (total plasma volume x 1) and HV (total plasma volume x 1.5-2) PLEX.

Results

Forty two ALF patients (median age: 23.5 years; females: 57.1%; MELD Na: 34.67 ± 6.07; SOFA score- 5.24 ± 1.42) underwent PLEX. Of these, 22 patients underwent SV-PLEX, and 20 underwent HV-PLEX. The mean age, sex, etiology distribution, and severity scores were similar between the groups. The median number of PLEX sessions (2) was similar in both groups. On Kaplan-Meier analysis, TFS was 45.5% in SV group and 45% in HV group (P = 0.76). A comparable decline in total bilirubin, PT/INR, ammonia, and MELD Na scores was noted in both groups. The cumulative number of adverse events was similar between the HV group (77.3%) and SV group (54.5%; P = 0.12).

Conclusions

SV PLEX is safe and as effective as HV PLEX in patients with ALF. Further randomized controlled trials with a larger sample size are needed to validate these findings.

Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

BACKGROUND

The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and pharmaceuticals. However, no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in humans. This study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide poisoning.

METHODS

This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July 2022. The entire course of the incidents was described in detail. Blood 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass spectrometer. Hematoxylin and eosin staining was performed to assess liver injury, and immunofluorescence was used to evaluate hepatic mitophagy.

RESULTS

The 2-amino-5-chloro-N,3-dimethylbenzamide powder (99% purity) entered the human body mainly via the skin and respiratory tract due to poor personal protective measures. The typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency, rash, fever, organic damage, and recovery phases in accordance with the clinical evolution. Rash and fever may be the important premonitory symptoms for further organ injuries. The chemical was detected in the blood of all patients and caused multiple organ injuries, predominantly liver injury, including kidney, myocardium, and microcirculation. Three patients recovered smoothly after comprehensive treatments, including artificial liver therapy, continuous renal replacement therapy, glucocorticoids, and other symptomatic and supportive treatments. One patient survived by liver transplantation. The postoperative pathological findings of the removed liver showed acute liver failure, and immunofluorescence staining confirmed the abundance of mitophagy in residual hepatocytes.

CONCLUSIONS

This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning. The chemical enters the body through the respiratory tract and skin during industrial production. The 2-amino-5-chloro-N,3-dimethylbenzamide poisoning causes multiple-organ dysfunction with a predominance of liver injury. Liver transplantation may be an effective option for patients with severe liver failure. The mechanisms of liver injury induced by 2-amino-5-chloro-N,3-dimethylbenzamide might involve abnormal mitochondrial function and mitophagy.

Liver Transplantation for Acute Liver Failure Due to Yellow Phosphorus Poisoning - A Comprehensive Review

Yellow phosphorus or metal phosphide (YP-MP) rodenticide poisoning has been a known cause of acute liver failure (ALF) in many countries of Asia and North and South America over the last decade. It is a highly toxic compound and is a well-known cause of intentional or accidental poisoning in both adults and children. In lower doses, it causes gastrointestinal symptoms and mild hepatic injury, and patients may spontaneously recover. In higher doses, hepatic necrosis and fatty infiltration may cause significant injury and may even lead to ALF, characterized by hepatic encephalopathy, coagulopathy, and lactic acidosis. Cardiotoxicity, rhabdomyolysis, and neutropenia are other well-documented complications. If untreated, it may lead to multi-organ dysfunction and death. Plasmapheresis and continuous renal replacement therapy (CRRT) have been used with limited success in patients who do not recover spontaneously. However, patients who develop ALF often need liver transplantation (LT). Liver transplantation has been successfully performed in ALF due to YP-MP poisoning in several countries, with good results in both adult and pediatric patients. Separate criteria for LT are important to ensure early and rapid listing of critical patients on the waiting list. The success rates of LT for ALF due to YP-MP rodenticide poisoning are very promising, provided there are no contra-indications to transplant. Plasma exchange, CRRT, or cytosorb can be used as a bridge to transplant in selected patients. In the long term, only with an increase in public awareness and sale restrictions can we prevent the intentional and accidental poisoning caused by this easily available, highly toxic compound.

Liver Transplantation for Acute Liver Failure- Indication, Prioritization, Timing, and Referral

Acute liver failure (ALF) is a major success story in gastroenterology, with improvements in critical care and liver transplant resulting in significant improvements in patient outcomes in the current era compared to the dismal survival rates in the pretransplant era. However, the ever-increasing list of transplant candidates and limited organ pool makes judicious patient selection and organ use mandatory to achieve good patient outcomes and prevent organ wastage. Several scoring systems exist to facilitate the identification of patients who need a liver transplant and would therefore need an early referral to a specialized liver unit. The timing of the liver transplant is also crucial as transplanting a patient too early would lead to those who would recover spontaneously receiving an organ (wastage), and a late decision might result in the patient becoming unfit for transplant (delisted) or have an advanced disease which would result in poor post-transplant outcomes. The current article reviews the indications and contraindications of liver transplant in ALF patients, the various prognostic scoring systems, etiology-specific outcomes, prioritization and timing of referral.

Novel radiological technique to recognize acute liver failure caused by yellow phosphorous containing rodenticides

Yellow phosphorous rodenticide (YPR) poisoning is the commonest cause for acute liver failure (ALF) in southern and western India. Due to medicolegal issues, history of YPR ingestion may not be available. As early recognition of YPR poisoning is important and there are no specific biochemical assays, other early predictors to identify this entity is necessary. We evaluated the diagnostic role of plain computed tomography (CT) in identifying YPR-induced ALF. All patients admitted to the liver unit with a diagnosis of ALF underwent a plain CT scan abdomen. Demographic details, clinical history, laboratory parameters, liver attenuation index (LAI) calculated on CT scan, treatment details, need for liver transplantation and clinical outcome were analyzed. Parameters for YPR-induced ALF (ALF-YPR) and other causes (ALF-OTH) were compared. Ability of LAI to distinguish ALF-YPR and ALF-OTH was analyzed using receiver operating characteristic (ROC) curve analysis. Twenty-four patients (15 female [62.5%]) were included in the study. Thirteen patients (54%) had YPR poisoning, while the rest formed the ALF-OTH group (11,46%). ALF-YPR patients had higher transaminase levels, lower peak serum bilirubin levels. ALF-YPR livers had significantly lower LAI as compared to ALF-OTH (- 30 vs. - 8, p = 0.001). On ROC curve analysis, an LAI greater than - 18 ruled out YPR as the cause for ALF with 91% sensitivity and 85% specificity. On regression analysis, LAI was the only independent factor predicting ALF-YPR (odds ratio - 0.86, [0.76, 0.96] p = 0.008). Our data shows that LAI on plain abdominal CT scan can be used to quickly recognize ALF-YPR in unclear cases so that necessary treatment protocol can be activated, or patient transfer arranged. Our analysis shows that an LAI greater than - 18 can reliably rule out YPR ingestion as the cause for ALF.

Improving Transplant-free Survival With Low-volume Plasma Exchange to Treat Children With Rodenticide Induced Hepatotoxicity

Background

In a prior report, no patient with rodenticidal hepatotoxicity who met Kochi criteria (MELD score ≥36 or baseline INR ≥6 with hepatic encephalopathy) (PMID: 26310868) for urgent liver transplantation survived with medical management alone. Plasma exchange (PLEX) may improve survival in these patients.

Objectives

We describe our experience with low-volume PLEX (PLEX-LV) in treating rodenticide ingestion induced hepatotoxicity in children.

Methods

From prospectively collected database of rodenticidal hepatotoxicity patients managed as in-patient with department of Hepatology from December 2017 to August 2021, we retrospectively studied outcomes in children (≤18 years). Hepatotoxicity was categorized as acute liver injury (ALI, coagulopathy alone) or acute liver failure (ALF, coagulopathy and encephalopathy). Kochi criteria was used to assess need for urgent liver transplantation. The primary study outcome was one-month survival.

Results

Of the 110 rodenticidal hepatotoxicity patients, 32 children (females: 56%; age: 16 [4.7-18] years; median, range) constituted the study patients. The study patients presented 4 (1-8) days after poison consumption (impulsive suicidal intent:31, accidental:1). Twenty children (62%) had ALI [MELD: 18 (8-36)] and 12 (38%) had ALF [MELD: 37 (24-45)].All children received standard medical care, including N-acetyl cysteine; ALF patients also received anti-cerebral edema measures. None of the patient families opted for liver transplantation. Seventeen children (ALI: 6, ALF: 11) were treated with PLEX-LV (3 [1-5] sessions, volume of plasma exchanged per session: 26 [13-38] ml/kg body weight) and peri-procedure low dose prednisolone.At 1 month, 28 of the 32 children (87.5%) were alive (4 ALF patients died). Of 10 children who met Kochi listing criteria for urgent liver transplantation, two children were ineligible for PLEX-LV (due to hemodynamic instability) and of the remaining 8 children treated by PLEX-LV, 6 (75%) survived.

Conclusions

PLEX-LV shows promise as an effective non-liver transplant treatment in children with rodenticidal hepatotoxicity.

Rodenticide ingestion is an important cause of acute hepatotoxicity in Tamil Nadu, southern India

BACKGROUND AND AIM

Though rodenticidal hepatotoxicity is reported from India, there is no systematic study to assess its magnitude. This study aimed to assess exposure to rodenticide as a risk factor for acute hepatotoxicity in Tamil Nadu, India.

METHODS

We retrospectively analyzed acute hepatotoxicity caused by ingestion of hepatotoxin or potentially hepatotoxic drug overdose across 15 hospitals in 6 districts of Tamil Nadu from 1 January 2019 to 30 June 2019. Study exclusion criteria were idiosyncratic drug-induced liver injury and chronic liver diseases.

RESULTS

Of the 702 patients, 685 gave history of consuming rodenticide; hepatotoxicity in the other patients resulted from paracetamol overdose (n=10) and due to other drugs (n=7); 97% patients had a suicidal intent. Of 671 patients with complete data, ratio of number of patients with hepatotoxicity due to rodenticide to paracetamol overdose was 450:6 (i.e. 75:1). The 451 rodenticidal hepatotoxicity patients (255 males, 75% were 15-34 years old) underwent conservative management (n=396), plasma exchange (n=54) and plasma exchange followed by liver transplant (n=1); 159 patients (35%) had poor outcome (131 died, 28 discharged in moribund state). Based on our observations, we estimate a case burden of 1584 rodenticidal hepatotoxicity patients (95% CI: 265-6119) with poor outcome in 554 patients in Tamil Nadu from January 2019 to June 2019. Population attributable risk for rodenticide as cause of hepatotoxicity was 22.7%.

CONCLUSION

Rodenticide ingestion was an important cause of acute hepatotoxicity in Tamil Nadu. Most patients were young and one-third had poor outcome. Public health interventions are needed to address this.