Introduction:
Clinical manifestation of organophosphates toxicity may be differentiate and include cholinergic toxidrome, intermediate syndrome, OP-induced delayed polyneuropathy to chronic OP-induced neuropsychiatric disorder (OPIDN). Patients symptoms, along with decrease in cholinesterase serum level, determines the possible diagnosis of organophosphate poisoning.

Objective:
The aim of the study was to present the clinical manifestation and cholinesterase level changes in intoxication with organophosphorus compounds in patients.

Material and methods:
A data base was created by analysis of the hospital documents of 34 patients hospitalized due to organophosphate intoxication. Statistical analysis involved frequency tables with percentage values, the application of non-parametric Chi-square test and parametric t-Student test (with homogeneity of variance Levine test). The level of static significance was set to p=0.05.

Results:
In fatal hospitalizations (20.6%), cholinesterase level was significantly lower (265.87 U/l) than in other patients (4254.78 U/l; p<0.05). Similarly, levels of cholinesterase were decreased in group of patients with acute respiratory failure (999.79 U/l vs 4943.86 U/l in other patients; p<0.05), patients with multi-organ dysfunction syndrome (244.13 U/l vs 4914.89 U/l in other patients; p<0.05) and those with cardiac arrest (547 U/l vs 4636.25 U/l in other patients). A statistically significant difference was also observed in cholinesterase level of patients who required mechanical ventilation (548.17 U/l vs 5219.71 U/l in other group). The study revealed that 29.4% of poisonings were suicidal

Conclusions:
The management of a patient with organophosphate poisoning remains challenging and requires continuous control. A significant step in the diagnostic process is the assessment changes in both the clinical picture and cholinesterase level.