Addition of immunosuppressive treatment to hemoperfusion is associated with improved survival after paraquat poisoning: a nationwide study

Abstract

Paraquat poisoning associates very high mortality rate. Early treatment with hemoperfusion is strongly suggested by animal and human studies. Although the survival benefit of additional immunosuppressive treatment (IST) in combination with hemoperfusion is also reported since 1971, the large-scale randomized control trials to confirm the effects of IST is difficult to be executed. Therefore, we designed this nationwide large-scale population-based retrospective cohort study to investigate the outcome of paraquat poisoning with hemoperfusion and the additional effects of IST combined with hemoperfusion. This nationwide retrospective cohort study utilized data retrieved from the National Health Insurance Research Database (NHIRD) of Taiwan. A total of 1811 hospitalized patients with a diagnosis of paraquat poisoning who received hemoperfusion between 1997 and 2009 were enrolled. The mean age of all 1811 study subjects was 47.3 years. 70% was male. The overall survival rate was only 26.4%. Respiratory failure and renal failure were diagnosed in 56.2% and 36% patients. The average frequency of hemoperfusion was twice. IST was added in 42.2% patients. IST significantly increases survival rate (from 24.3% to 29.3%, P<0.001). The combined IST with methylprednisolone, cyclophosphamide and dexamethasone associates with the highest survival rate (48%, P<0.001). Moreover, patients younger than 45 years of age in the IST group had the best survival (41.0% vs. 33.7%, p<0.001). Our results support the use of IST with hemoperfusion for paraquat-poisoned patients. The best survival effect of IST is the combination of methylprednisolone, cyclophosphamide and daily dexamethasone, especially in patients with younger age.

Figure 1. Selection and grouping of the patients with paraquat poisoning.

Abbreviations: IST: Immunosuppressive treatment.

Figure 2. Kaplan-Meier survival plot of the IST group (n = 765) versus the non-IST control group (n = 1046, log-rank test, p< = 0.001).

Figure 3. Treatment effects of different immunosuppressive regimens in paraquat-poisoned patients with hemoperfusion treatment.

Cox regression analysis of mortality rates among different treatment groups, adjusted for age and sex, was used to calculate the hazard ratio. Abbreviations: No IST: No immunosuppressive treatment (Hemoperfusion alone); IST: Immunosuppressive treatment; MP: Methylprednisolone; CP: Cyclophosphamide; DEX: Dexamethasone.

Figure 4. Kaplan-Meier survival plot of the MP+CP+DEX subgroup (n = 100) versus the non-IST group (n = 1046, log rank test, P<0.001).

Abbreviations: MP: Methylprednisolone; CP: Cyclophosphamide; DEX: Dexamethasone; IST: Immunosuppressive treatment.

Figure 5. Comparison of survival day before mortality in paraquat-poisoned patients with additional different combined immunosuppressive regimens and hemoperfusion.

Cox regression analysis of mortality rates among different treatment groups, adjusted for age and sex, was used to calculate the hazard ratio. All patients received hemoperfusion. Abbreviations: No IST: No immunosuppressive treatment (Hemoperfusion alone); IST: Immunosuppressive treatment; MP: Methylprednisolone; CP: Cyclophosphamide; DEX: Dexamethasone.