The Use of Isocapnic Hyperventilation (iHV) for Treatment of Methanol Poisoned Patients
试验速览
- 阶段
- 1 期
- 状态
- 撤回
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Characterization of methanol elimination kinetics, when iHV is utilized
研究概览
简要总结
The projects investigate if treatment with isocapnic hyperventilation can eliminate methanol from the body in a similar manner to dialysis. This is achieved by administering the antidote (fomepizole) and let the patient breathe on a isocapnic hyperventilation device while samples of blood, urine and maybe the breath are collected to measure the contents of methanol and its metabolites.
详细描述
Isocapnic hyperventilation (iHV) The normal physiology breathing is a careful balance between the number of breaths per minute (rate/min) and the depth of each breath (tidal volume, Vt). Together they make up the minute ventilation (MV), where MV= rate x Vt). To maintain stable homeostasis in the organism, the minute ventilation is closely regulated to maintain adequate uptake of oxygen and adequate elimination of the carbon dioxide (CO2) that is produced by the metabolism. Too low minute ventilation leads to a buildup of CO2 and decrease in blood pH (respiratory acidosis), while hyperventilation (too high minute ventilation) leads to an excess loss of CO2 and increase in blood pH (respiratory alkalosis). The same mechanism will also enable the organism to compensate any metabolic disturbances (up to a certain point): A metabolic acidosis will be counteracted by a hyperventilation, whereas a metabolic alkalosis will be counteracted by a hypoventilation, both with the ultimate goal of keeping the acidity (as given by the pH) as closely regulated as possible.
The concept of isocapnic hyperventilation (iHV) allows the person to hyperventilate while keeping the CO2 within normal limits at the same time. The ClearMate (Thornhill Research Inc., Canada) adds CO2 to the inspired air to compensate to the increased loss induced by the increased minute ventilation. This means that hyperventilation can occur, and a wash-out of volatile substances such as methanol will happen without disrupting the important CO2 balance.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adult patients, men & women diagnosed with methanol poisoning
- •Serum-methanol ≥ 50 mg/dL (16 mM)
- •pH ≥ 7.0, and correctable by bicarbonate infusion
- •no (newly developed) visual disturbances
排除标准
- •Acidosis requiring haemodialysis (pH <7.0), or acidosis that is not responding in spite of aggressive buffer (bicarbonate) treatment within maximum 1-2 hours.
- •Comatose patients
- •Newly developed visual disturbances
- •ADH not fully blocked with antidotes, and not responding to additional dosing of fomepizole. Will be identified by a continuous or increasing anion gap (AG) or Base Excess (BE) on the blood gas machine.
研究组 & 干预措施
Isocapnic hyperventilation (iHV)
Loading dose of fomepizole on clinical suspicion; A) History of intake of alcohol of unknown/illegal origin plus symptoms potentially occurring from methanol, or B) history as above and verified methanol poisonings among people drinking the same alcohol, or C) metabolic acidosis of unknown origin (where methanol cannot be excluded as the cause;or D) a combination of these.
● iHV started after a S-methanol concentration > 50 mg/dL is obtained (typically within 4 hours) and initial acidosis is partly or fully corrected by sodium bicarbonate (BD <15mM, HCO3- >10mM)
干预措施: isocapnic hyperventilation (Device)
结局指标
主要结局
Characterization of methanol elimination kinetics, when iHV is utilized
时间窗: 0-40 hours
T1/2 S-methanol (t1-t2) during iHV: Half-life of methanol in blood from start (t1) to end (t2) of treatment with iHV T1/2 S-methanol (t0-t1) before iHV): Half-life of methanol in blood from t0 to t1 before start of treatment with iHV for evaluation of individual differences in kinetics
次要结局
- Tolerability by self reporting by patient(0-40 hours)
- Elimination ratio of formate(0-40 hours)
- Elimination ratio of methanol(0-40 hours)
- Feasibility of use of iHV in Iran(0-40 hours)
- Need for haemodialysis(0- 40 hours)
- Adverse events(through study completion, estimated 2 years)
- Characterization of methanol elimination kinetics, prior to iHV is utilized(0-40 hours)
- Serum formate kinetics(0-40 hours)
- Implementation of fomepizole in Iran(through study completion, estimated 2 years)
- Evaluation of fomepizole elimination during iHV(0-4 hours)
- Length of ICU- and hospital stay(from stdy start to death or discharge ICU, expected average 30 hours)
研究者
Knut Erik Hovda, MD, PhD
Senior Consultant & Professor
Oslo University Hospital