1907 BMJ (Clinical Research Edition)  
IN discussing poisoning by coal gases and illuminating ;gases, T. A. Maass (Berl. kin. Woch., December 10th, 1906) points out that the gases evolved in the combustion of coal -contain varying quantities of carbon monoxide, which has been given by certain observers at from 0.34 per cent. to 2.5 per cent., while the remainder consists of carbon -dioxide, oxygen, nitrogen, and traces of hydrocarbons. As a rule, the percentage is about 0.54 per cent. of carbon monoxide. Illuminating gas contains
more » ... ing gas contains somewhat higher ,percentages of carbon monoxide. When made from coal, it contains from 5 to 10 per cent. of carbon monoxide. The lungs are capable of taking up carbon monoxide very rapidly, and the whole body is soon affected by the zabsorbed gas. He divides the course of carbon monoxide poisoning roughly into four stages. The first stage is met with almost immediately after inhaling air containing .considerable quantities of this gas, and is evidenced by -extremely severe headache, lacrymation, buzzing in the -ears and throbbing in the temples, sleepiness, feeling of languor, and incapability of standing up or moving about. The first sign is frequently nausea and vomiting, while the respirationis rapid and irregular atfirst, and becomes rattling and slower in a short time. Apart from these symptoms, the psychical condition undergoes a change, and close resemblance to alcoholic drunkenness is noticed. The mental condition accounts for the failure to get out of the poisonous atmosphere, which is so often remarked. The person realizes to a certain degree the danger surrounding him, but, having lost the capability of thinking clearly, often neglects to open the window, or to get out -of the room. The author gives an example of this in the case of a medical man who was overcome by the effects of coal gas, and describes his own symptoms. The second stage chiefly attacks the motor apparatus. The muscular irritability is increased, and even convulsions may occur, or there may be clonic contractions and trismus. The symptoms of the first stage continue, and there may be increased salivation in addition in this stage. The third stage is characterized, first by anaesthesia of the skin and next by the failure of the voluntary muscles and by asphyxia. Consciousness is most retained during this stage. The last stage follows when death does not occur during the third stage and when recovery does not take place directly. This stage consists of an extraordinary variety of sequelae, many of which often end fatally. Maass believes that no other poison leads to such a variety of late effects. Before dealing with these late symptoms, he discusses the pathology of carbon monoxide poisoning briefly. The gas has a peculiar affinity for the haemoglobin of the blood, and it is not surprising that all organs are rapidly affected. Of all the theories on this poisoning, the one which appeals to him as being the most plausible is that which assumes that the oxygen is replaced by the carbon monoxide, and the blood charged with this gas -circulating through theorgans interferes with thelocal nutrition, and thus produces changes. That the central nervous system should be most severely affected is not to be wondered at, if one remembers the delicate way which nervous tissue reacts to changed conditions of nutrition. He then deals shortly with some of the typical post-mortem changes. Turning to the diagnosis, the symptoms may give rise to confusion with drunkenness and even to the early stages of enteric fever, but the blood offers a certain differential diagnosis. He describes Reetz's modification of Wachholz and Sieratzki's test: 4 of blood is dissolved in a test tube by shaking gently; 40 drops of a 1 in 9 solution of the £erricyanide of potassium are then added. After this has been carefully mixed, one half is carefully poured off into a second test tube, and this is corked and put aside. The remaining half is well shaken by pouring into a dish and back into the test tube several times for ten minutes, and then to both parts 5 drops of ammonium sulphide and 10 of a 20 per cent. solution of tannin are added. If carbon monoxide is present, the shaken tube will be found to contain a greyish-green precipitate, and the unshaken tube a more or less distinctly pink precipitate, while it no carbon monoxide is present, both will show the greyishgreen precipitate. This test can be carried out with blood which has stood for years, and is therefore of great forensic importance. The test, however, is only of use when the doctor is called too late for treatment. If he arrives in time, he must devote all his attention to the patient. He describes the usual methods of treatment, including artificial respiration, inhalation of oxygen, electricity, etc. He also deals with the differences between pure carbon monoxide poisoning and poisoning by illuminating gas. The lethal dose is sufficient to prove that the carbon monoxide element of the latter is not the only toxic agent. Sachs has compared the differences, and shows very marked variations of symptoms in two forms. The latter is about two and a half times more poisonous than pure carbon monoxide. 77. Dosage of Tuberulin. LoWENSTEIN AND KAUFFMANN (Zeit. f. Tuberk. und Heilstatt., Bd. X, Heft 1, 1906) recommend that for purposes of diagnosis the dose of the" old tuberculin" should not, as Koch advised, be increased when no reaction follows the first dose, but that in order to obtain a reaction the same amount of 0.2 mg. should be injected if necessary four times over within from twelve to sixteen days, and only when these injections have caused no reaction should larger doses be employed. The method recommended by the authors is espocially suitable for cases of recent tuberculosis with doubtful physical signs-that is, juist for those cases in which a correct diagnosis is of the greatest importance. The method is based upon the fact that the first inijection, even if no obvious reaction occurs, yet temporarily increases the sensitiveness of the organism towards a second injection, and the second again towards a third. This increase of susceptibility is best seen when the amount of tuberculin used is small, and it is so well marked that the reaction after the fourth injection of 0.2 mg. may be little less in intensity than that after a single dose of 10 mg. After the first four injections, if no reaction has been obtained, the dose is increased to 2 mg., then to 5 mg., and finally to 10 mg. The injections are made in the morning; the patient is kept at rest in bed, and the temperature is taken every three hours. The reaction, according to Koch's rule. is considered positive if the temperature rises at least 50 higher than the mean temperature and there are at the same time marked subjective symptoms. A three days' interval at least is left between each injection. A tendency to haemorrhages and heart affections, when they are not too advanced and occur in young people do not contraindicate the use of tuberculin, but the injection should not be made in cases where kidney disease or pregnancy is present. The following are the important points in determining the value for diagnostic purposes of any new method of injection: (1) That tuberculous patients react to the injections; (2) that sound persons fail to react; and (3) the effect upon healed tuberculosis. In 62cames of undoubted tuberculosis with bacilli in the sputum, 51 reacted to one of the four initial injections. In 10 of the remaining cases, 8 of which reacted at the fifth injection, that of 2 mg., the explanation that in cases of old tuberculosis with a strongtendency to recovery the resistance of the organism to tuberculin is greatly increased, was a satisfactory one. The remaining case, which reacted at the second injection of 10 mg., is inexplicable to the authors. The second question, as to the possibility of a sound person reacting to the injections, needs no great consideration. If reaction under the old method of quickly-increasing doses is held to be decisive as to the presence of tuberculosis, much more must this be the case when injections of small quantities only are employed. As to the reaction of persons with healed tuberculosis, while it is certain that resistance in such cases may be increased, it is not possible to fix upon a dose of tuberculin such that absence of reaction to it shall definitely occasion a diagnosis of healed tuberculosis; the authors iaeline totheviewof Bandaliers, who wouldchoosethe dose of 10mg. Of 300 cases treated by the method of repeated injections of 12 mg., 69, or 23 per cent., reacted at the first injection; 73, or 24.3 per cent., at the second; 107, or 35.7 per cent., at the third ; and 51, or 17 per cent., at the fourth. The greatest number of reactions thus followed the third injection; 242 of the cases were in the first stage of phthisis, and of these 99, or 40 per cent., reacted at the third injection. The reaction obtained was not very different from that obtained by the older method, and the 386 A
doi:10.1136/bmj.1.2407.e25 fatcat:rs3fhm7gizc2tipzq23c74flxu