Hyperbaric oxygen therapy for severe hydrogen sulfide poisoning

The optimum therapy for hydrogen sulfide poisoning is unclear. Adjuncts used in the treatment of cyanide poisoning have been advocated because of the shared mechanism of toxicity between hydrogen sulfide and cyanide. Following success in cyanide poisoning, hyperbaric oxygen therapy (HBO) has been suggested for use in treating hydrogen sulfide poisoning. A case of severe hydrogen sulfide poisoning was successfully treated with HBO after standard therapy was apparently ineffective. HBO as a therapeutic adjunct in hydrogen sulfide poisoning and the rationale for its use are discussed.

Clinical efficacy of niludipine in the treatment of angina pectoris

Some Ca2+-antagonists are used for the treatment of angina pectoris. In the present study niludipine (Bay a 7168) was assessed in various types of angina pectoris cases. Niludipine, a Ca2+-antagonist of the dihydropyridine derivatives, was administered to 50 patients, 27 with effort angina pectoris, 4 with rest angina, 7 with effort plus rest angina, 4 with variant angina, 8 with angina following myocardial infarction in the doses of 60 mg/day or 120 mg/day for 4 weeks and the changes of subjective symptoms and objective findings were evaluated. Improvement was found by 69.6% for effort angina, by 75% (3/4) for rest angina, and side effects by 6% but mild degree--no facial flash, headache, hypotension were observed. The results suggest that niludipine is a safe antianginal Ca2+-antagonist with broad effectiveness for various types of angina pectoris.

Long-term results of prospective randomised study of coronary artery bypass surgery in stable angina pectoris. European Coronary Surgery Study Group

This report presents the final results (follow-up 5--8 years) of a prospective study in 768 men aged under 65 with mild to moderate angina, 50% or greater stenosis in at least two major coronary arteries, and good left ventricular function. 395 were randomised to coronary artery bypass surgery, 373 to no treatment; 1 patient in the surgery group was lost to follow-up. These original groups were compared, whatever subsequently happened to the patients. Survival was improved significantly by surgery in the total population, in patients with three-vessel disease, and in patients with stenosis in the proximal third of the left anterior descending artery constituting a component of either two or three vessel disease, and non-significantly in patients with left main coronary disease. An abnormal electrocardiogram at rest, ST-segment depression greater than or equal to 1.5 mm during exercise, peripheral arterial disease, and increasing age independently point to a better chance of survival with surgery. In the absence of these prognostic variables in patients with eigher two or three vessel disease the outlook is so good that early surgery is unlikely to increase the prospect of survival. In terms of anginal attacks, use of beta-adrenergic blockers and nitrates, and exercise performance the surgical group did significantly better than the medical group throughout the 5 years of follow-up, but the difference between the two treatments tended to decrease.

The treatment of hydrogen sulfide intoxication: oxygen versus nitrites

A case of severe H2S intoxication, treated with oxygen, respiratory support and thiopental cerebral protection, is presented. The usual antidotal treatments using nitrites or oxygen are discussed, examining the risks of nitrite use and the efficacy of oxygen. The successful outcome of the case presented suggests that H2S poisoning be treated with oxygen and vigorous organ supportive care.

Nitrite as antidote for acute hydrogen sulfide intoxication?

The detoxification of hydrogen sulfide (H2S) by a heme catalyzed oxidation was examined as part of an on-going study of H2S toxicity. Interlocking O2 absorption and sulfide depletion data indicate that both oxyhemoglobin and methemoglobin are effective catalytic agents. Although the latter is more efficacious, the life time of excess sulfide in the presence of oxygen and either of the above is of the order of minutes. It has also been established that the formation of methemoglobin following nitrite administration occurs preferentially under oxygen poor conditions. Under an atmospheric or oxygen enriched environment, which favors sulfide depletion, the nitrite retards sulfide oxidation. Thus nitrite as an antidote for acute H2S intoxication can only be effective within the first few minutes after the exposure, at which time resuscitation and/or ventilation of the victim is likely to produce conditions in which the nitrite actually slows sulfide removal.

[Effect of nitroglycerin and sodium nitrite on myocardial mitochondrial respiration and oxidative phosphorylation normally and in coronarogenic ischemia]

The effect of nitroglycerin and sodium nitrite (2.10(-6), 2.10(-5) and 2.10(-4) g/ml) on respiration and oxidative phosphorylation of mitochondria of the normal and ischemized dog myocardium has been investigated in the presence of glutamate, succinate and alfaketoglutarate. The drugs inhibited ADP-activated oxygen consumption and ADP phosphorylation rate upon oxidation of succinic acid formed in mitochondria from exogenic glutamate, without changes in the phosphorylation coefficient and free oxidation rate (i. e. in the absence of ADP) in mitochondria of the healthy and ischemic heart. In the ischemic area one can also observe an inhibition of ADP-activated oxidation of endogenic succinate formed from exogenic glutamate.

Cyanide intoxication in sheep: enhancement of efficacy of sodium nitrite, sodium thiosulfate, and cobaltous chloride

For treatment of cyanide intoxication of ruminants, the present recommended doses of sodium nitrite (5 mg/kg of body weight) and sodium thiosulfate (25 to 50 mg/kg) are smaller than those recommended for other animals; the decrease is partially attributed to the greater susceptibility of ruminants to the toxic effects of sodium nitrite. Based on the high tissue concentration and activity rate of rhodanese in ruminants, sulfur donors such as sodium thiosulfate could be utilized more efficaciously. Doses of sodium nitrite and sodium thiosulfate (up to 22 and 660 mg/kg, respectively) were evaluated in the present studies. Adjustment of the antidotal combination provided almost three times the protection afforded by the previously recommended doses. Moreover, under the conditions tested, the newly adjusted dose levels of sodium thiosulfate alone were more effective than the previously used antidotal combination of sodium nitrite and sodium thiosulfate and this protective effect was enhanced by cobaltous chloride (10.6 mg/kg) or sodium nitrite. The present recommended therapeutic approach to cyanide intoxication in sheep should be based primarily on administration of a much higher dose of sodium thiosulfate in combination with sodium nitrite or cobaltous chloride (or both).