医学ppt课件農藥中毒

農藥中毒 楊振昌醫師 國立陽明大學醫學系內科暨 臺北榮民總醫院內科部臨床毒物科 農藥 (Pesticides) 保護農作物及其生產物或改良作物目的 所用之化學藥品 農藥之種類 ： 殺菌劑 (Fungicide) 殺蟲劑 (Insecticide) 除草劑 (Herbicide) 殺蹣劑 (Acaricide, Miticide) 農藥 (Pesticides) 殺線蟲劑 (Nematocide) 殺鼠劑 (Rodenticide) 引誘劑 (Attractant) 忌避劑 (Repellent) 植物生長調節劑 (Plant growth regulator) 補助劑 (Supplemental agent) 歐洲及中國於公元前即有使用硫黃 、 東蕓 草 (Hellebore) 及 紅海蔥 (red squill) 之記錄 十九世紀後，農藥使用日益增加 (CS2 、 除 蟲菊精 、 硫酸銅 、 砷酸鉛等 ) 1939年 ： DDT被發現具良好殺蟲效果 1944年 ： 發現巴拉松 (Parathion) 1950年 ： 殺菌劑保米黴素 (Blasticidin-S) 其後 各種除草劑 、 殺蟲劑陸續被製造 農藥之沿革 殺蟲劑 (Insecticides) 植物性殺蟲劑：如除蟲菊 有機氯劑：如安殺番 有機磷劑：如大滅松 氨基甲酸鹽：如安丹 有機氮劑：如培丹 有機氟素劑：如 Fussol 其他及雜類：如溴化甲烷 除草劑 /殺菌劑 選擇性除草劑 ： 如 2-4-D 、 草滅淨 、 嘉磷 塞異丙 胺 鹽 非選擇性除草劑 ：如巴拉刈 、五氯酚鈉 撒佈用殺菌劑 ：如波爾多 、 錳乃浦 、 三 苯醋錫、快得寧 種子消毒劑 ：如免賴得 土壤消毒劑：如福馬林 果實保護劑：如硫尿素 其他農藥 殺蹣劑 ：如克氯苯 殺線蟲劑：如巴拉松、二溴氯丙烷 殺鼠劑：如殺鼠靈 (短效 )或得伐鼠 植物生長調節劑：植物荷爾蒙 補助劑 ：包括 展著劑 (spreader)、 增量劑 (diluent)、 溶劑 (solvent) 、 乳化劑 (emulsifier) 、 協力劑 (synergist) 、 固著劑 (sticker) 、 分解防止劑 (stabilizer) 農藥型態 液劑： (1)液體狀： 溶液、乳劑、水懸： 粉； (2)粉狀 ：可濕性粉劑、可溶性粉劑 粉劑 粒劑 煙霧劑 燻蒸劑 錠劑 油劑 . 理想的農藥 低毒性 效力大 無藥害 品質安定 價格低廉 物理性質好 使用簡單，可混用 . 農藥 (Pesticides) 可依據半致死劑量 (LD50)作簡單之分類 5,000mg/kg： 無毒性 500-5,000 mg/kg： 低毒性 50-500 mg/kg： 中毒性 5-50 mg/kg： 強毒性 =140/min) *cholinesterase佔標準值之比率 Atropine In tachycardia： first correct the possible causes of tachycardia, such as dehydration, fever, hypoxemia, hypotension In tachycardia： If tachycardia persists or worsens after atropine usage and other possible factors have been corrected, decreased dose of atropine or change parenteral atropine to inhalation atropine should be warranted In fever： differential diagnosis between atropine overdose and infection (especially aspiration pneumonia) is indicated Pralidoxime (2-PAM) Indication： reactivates acetylcholinesterase and antagonizes nicotinic effects of OPS poisoning Dosage: 1-2gm (pediatric dose 25-50 mg/kg) over 30 minutes, repeat the dose every 6-12 hours; OR 500mg/hr (maximum dose 12gm/day) Usual treatment： 3 days; longer therapy maybe needed on few occasions Rapid infusion ( 500mg/min) or large dose： dizziness, headache, nausea, neuromuscular blockade, inhibition of cholinesterase, weakness, blurred vision, diplopia, tachycardia, CPK response to low-dose atropine, RBC OR 0.004- 0.016mg/kg/min, adjust the dosage by the amount of bronchial secretion (not by heart rate or pupil size!) Course of therapy depends on the clinical severity Should be used with caution in patients with BPH, glaucoma, high fever, hypertension, hypothyroidism Adverse effects： anticholinergic manifestations, e.g. dry mouth, decreased intestinal motility, mydriasis, urine retention, tachycardia, fever, psychosis, hallucination, seizures, coma, ventricular dysrrhythmias Pralidoxime (2-PAM) The use of PAM in patients with carbamate insecticide poisonings remains controversial Reasons proposed against the use of PAM (1). Rapid hydrolysis of carbamylated acetylcholinesterase (2). PAM, in high concentration, can react with anionic site of acetylcholinesterase and then inhibit enzymatic hydrolysis of acetylcholine (3). In anecdotal reports, PAM has been reported to potentiate the toxic effects of carbaryl (4). Possible toxicities of PAM Pralidoxime (2-PAM) Indication： concomitant organophosphate insecticide poisoning, severe toxic manifestations, requiring large dose of atropine, or insecticide poisoning with uncertain cause Dosage： 1-2gm (pediatric dose 25-40 mg/kg with total dose 500mg/min) or large dose may lead to neuromuscular blockade, inhibition of cholinesterase, weakness, blurred vision, diplopia, dizziness, headache, nausea, tachycardia, CPK possible aggravation of pulmonary edema Hemoperfusion maybe useful if it can be commenced within 2 hours of ingestion Longer duration of hemoperfusion ? Possible complications of hemoperfusion: thrombocytopenia, hypocalcemia, hypotension, hypoglycemia, hypothermia Treatment 巴拉刈除草劑中毒 N-acetylcysteine may be effective (limited evidence) Cyclophosphomide + corticosteroid: (1). 68% (41/61) mortality rate in untreated group vs. 28% (20/72) in treatment group (Addo but not all cases were confirmed by serum paraquat levels. (2). Survival in 18/22 patients (treated) vs. 12/28 patients (untreated) with moderate poisoning (Lin 1999); the data lost statistical significance when reanalyzed on an intention to treat basis (Buckley 2001) Treatment 巴拉刈除草劑中毒 (3). No difference in survival between groups (Perriens 1992) Possible complications of therapy: septicemia, alopecia, acne, infertility in female patients Vitamin C, vitamin E, sodium thiosulfate, colchicine, superoxide dismutase, radiotherapy.: lack of supporting clinical evidence NO inhalation maybe helpful (Koppel 1994) Hemodialysis if acute renal failure develops Lung transplantation： occasional survival Treatment 巴拉刈除草劑中毒 主成份 ： isopropylamine salted glyphosate (41%), polyoxyethyleneamine (a non-ionic surfactant, 15%) 俗稱 :年年春 ,好你春 ,好伯春 ,日日好 ,紅星 Color： brown yellow, pH 4.8 LD50 of glyphosate： 5,200 mg/kg Toxic mechanism： remains unclear but probably related to the surfactant polyoxyethyleneamine (GI tract irritation or ulcer, hypotension, diarrhea) 嘉磷塞異丙胺 鹽 除草劑中毒 年年春除草劑 Initial symptoms/signs： nausea, vomiting, sore throat, salivation, oral and GI tract ulcer (no severe injury) Later stage (6-8 hours)： diarrhea and abdominal pain (uncommon and maybe due to the frequent use of cathartics in treatment of poisoning) Other manifestations： conjunctivitis following splash contact, hypothermia, nystagmus, periorbital edema/burn, tachycardia, palpitation, erythema, contact dermatitis, hyperamylasemia, elevated liver enzymes, leukocytosis 嘉磷塞異丙胺 鹽 除草劑中毒 年年春除草劑導致輕度食道潰瘍 年年春除草劑導致眼睛發炎 年年春除草劑導致皮膚紅疹 Severe toxicity： metabolic acidosis, fever, hypotension, hypovolemia,acute renal failure, GI hemorrhage, ileus, hypoxia, bronchospasm, pulmonary edema, ARDS, seizure, hyperkalemia, cardiac arrhythmia, shock, coma Airway injury due to aspiration is likely to be the major cause of death： injury of the artenoepiglottic fold may indicate airway injury (Chang 1995) Mortality rate: 3%-11.3% Predictors of mortality： hyperkalemia, pulmonary edema, and metabolic acidosis (Lee 2000) 嘉磷塞異丙胺 鹽 除草劑中毒 Diagnosis： history and clinical manifestations; differential diagnosis between various herbicides Treatment： deconta