A correct view would probably include both factors: a conclusion which Horatio C. Wood reached eight years ago, when he said: "If any evidence is to be at tached to the statements of competent witnesses it is certain that in some cases, under the influence of chloroform, the pulse and respiration have ceased simultaneously, while in other instances the respiration has ceased before the pulse, and in still other cases the pulse has ceased its beat before the respiratory movements were arrested." Lauder Brunton has since given precision to our knowledge by an exhaustive study of the question, which led him, in the main, to believe that cases of simple danger without death were due to failure of respiration, while death was brought about through arrest of the heart or arrest of the heart and respiration to gether (neuroparalysis); furthermore, that the most common cause of neuro paralysis, as found by Casper, was strang ling (as in drowning), which kills by neuroparalysis as often as by asphyxia.
[Variations in circulation due not only to the above various factors, but also to alterations effected by chloroform in the central nervous system and local nervons mechanisms. As shown by \Valle'', elec trical reaction is profoundly altered by ana,stheties : hence distinct danger in con ditions of nerve-prostration and post-in fluenzal neurasthenia. The whole ques tion of reflex inhibition of the heart under chloroform bristles with difficul ties. If fear were simply the eause, such eases would occur often mider ether, as that substance, when badly given, pro duces more terror, breath-holding, and struggling, than chloroform ; and yet ether seldom, if ever, kills in this way. Unquestionably, chloroform — whether through poisonous effects on protoplasm or in some other way—exerts -some dele terious influence upon tissues of patients, which renders them less able to with stand any unusual strain imposed upon them. DUDLEY BUXTON, Assoc. Ed., An mm1, '96.1 Lowered arterial pressure has a com paratively feeble effect upon the respira tion, but, when the pressure falls suffi ciently, resTira tory depression does occur. Even excessive lowering of blood-pressure primarily stimulates the vasomotor cen tre, the sensibility of the centre being. evidently necessary to the automatic regulation of the eh-ciliation. Hence it is evident that the depression of the circu lation produced by chloroform has effect upon the respiratory centres only NVIICII the pressure has fallen very low, and, while it may be a factor in the produc tion of respiratory failure during chloro formization, the failure mnst be chiefly due to the direct influence exercised by tlie drug upon the respiratory centres. H. C. Wood and \V. S. Carter (Jour. of
Expel.. Med., May.. '97).
Arrest of the heart is one of the most important causes of collapse during chloroform auassthesia. The paralysis of the vasomotor centre which is provoked by the latter brings about the rapid fall of the blood-pressure, and this fall, by depriving the cardiac muscle of its ex citant, is one of the causes of the arrest of the heart. Evenhoilf (Vratch; Union Aled., July 11, '97).
The principal danger from chloroform anmstliesia is the sudden syncope from cardiac paralysis, which is as likely to occur in strong as in weak 'subjects; it happens more frequently at the begin ning than at the end of amesthetization, presents conditions of the greatest diffi cmIty for treatment. and frequently re sults in death. In view of these condi tions, although the superiority and greater convenience of chloroform in cer tain cases of cerebral surgery, operations on the respiratory passages, ete., may give it preference, its adoption as a rou tine amesthetic ought to be condemned. Editorial (Boston :Med. and Slug. Jour., Aug. 26, '97).
Out of some 2400 patients who were etherized, 10 developed temperatures with some respiratory complications, and all had gas before ether. Six of these had bronchitis,' pleurisy, and 3 broncho pneumonia, 1 of these last being, a fatal case. Seven of these cases occurred in summer. In none of these 10 eases was there previous history of bronchitis; all were in good condition and took the an mstlietic well. The operations were pro longed ones, and with 1 exception on the trunk. necessitating bandaging-, which would prevent free expectoration. A number of patients in bad condition from alcohol or sepsis, and subjected to short operations under ether without gas, did not develop any lung complica tion. These last patients, however, did not have to traverse corridors. Not one out of GOO chloroform cases, of which many were for mouth operations, de veloped any respiratory trouble.
Chloroform is recommended for all long operations on the trunk, or, if ether be given at tirst, it should be changed after a time for chloroform. Crouch and Corner (Lancet, May 24, 1902).
The heart also shares the brunt of responsibility with the respiratory tract as far as contra-indications are con cerned; but if the operator bears in mind the fact that, the nearer muscular integrity of the organ is discerned, the greater the safety', he will at once have a key to the lesion which may prove the basis of complications. Fatty degenera tion and dilatation are the main condi tions to fear, because the cardiac walls are the most compromised and may not be able to resist the engorgement result ing from increased arterial pressure.