Role of CVVH in Patients With Acute Paraquat Poisoning (PQ)

• Efficacy [ Time Frame: at 6 months after paraquat poisoning ] [ Designated as safety issue: No ]

  CVVH treatment efficacy was assessed by the following measurements:

  1. Mortality rate: compared the difference between standardized therapy and CVVH treatment.
  2. Number of organs involved in paraquat poisoning such as lung,kidney,liver and heart.
  3. Degree of organ injuries
  4. CT scan of lung
  5. Biomarkers:

  1)Oxidative stress: blood superoxide dismutase(SOD),malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT).

  2)Proinflammatory factors: interleukins(IL-2,IL-6,IL-8 and IL-10) 3)Kidney function:serum cystatin C and estimated GFR and N-acetyl-β-(D)-glucosaminidase activity (NAG),kidney injury molecule-1 (KIM-1), Neutrophil gelatinase-associated lipocalin(NAGL) and urinary retinol-binding protein(RBP),etc.

  4)Heart damage markers: cTnT，MYO，CK-MB and BNP.

  
  

• Safety of CVVH for the treatment of patients [ Time Frame: at 2 weeks after paraquat poisoning ] [ Designated as safety issue: No ]

  Safety and tolerability were assessed by the followings.

  1. Changes from baseline in systolic blood pressure and mean artery pressure during CVVH treatment procedure.
  2. Number of participants with adverse events such as bleeding, respiratory failure,hypotension,shock,thrombosis,pulmonary embolism and death.
  
  

Paraquat (1,1 '-dimethyl-4,4'-bipyridylium dichloride) is widely used as a herbicide. Accidental or intentional ingestion of paraquat is common in many developing countries such as China, Sri Lanka and Korea because of easy access. The high mortality rate of paraquat is due to its high toxicity and the lack of effective treatments. Thus, the paraquat poisoning becomes one of major medical problem in the developing countries.

Paraquat poisoning is also one of major causes of death among young patients with acute poisoning in China. It is characterized by multiple organ failure and pulmonary fibrosis with respiratory failure. A growing body of evidence suggested that continuous venovenous hemofiltration (CVVH) had a great beneficial role in the treatment of multiple organ dysfunctions. We hypothesized that CVVH might reduce the high mortality rate of paraquat poisoning via restoring the multiorgan function, such as acute hepatic lesion, acute kidney injury, acute lung injury and acute pancreatic injury. We expect to enroll 100 patients from our hospital within 1 week after oral intake of paraquat. All patients were randomly divided into Group 1 and Group 2. Group 1 (n=50) were treated with a standardized therapeutic regimen including stomach lavage, emergency haemoperfusion and drugs. Group 2 (n=50) were accepted with standardized treatment plus CVVH. The aim of this prospective clinical study was to evaluate the safety and efficacy of CVVH for the treatment of patients with paraquat poisoning. The survival rate, clinical manifestations and clinical parameters between these two groups were compared.