10 Crimean war, 23—21, 91 per cent.; Confederate army, (Sorrel), 66—60, 91 per cent.; U. S. army, 505—451, 89.3 per cent.; Italian war (Demme and Chenu), 176—162, 91 per cent.; Franco-German war (Poncet), 316—181, 57.28 per cent. (omitting Richter's 224 cases with only 107 deaths, the mortality of the remaining 92 cases (74) was 80 per cent.); St. Thomas's Hospital, 43—24, 55.8 per cent.; St. George's Hospital, 30—21, 70 per cent.; St. Bartholomew's Hospital, 63—47, 74.6 per cent.; Guy's Hospital, 60—51, 85 per cent.; Pennsylvania Hospital, 26—20, 76.9 per cent.; Boston City Hospital, 24—22, 91.6 per cent. The mortality-rate at Guy's (85 per cent.) is almost the same as that given by Poland for the period from 1825 to 1858 (86.1 per cent.).
As met with in private practice, under favorable hygienic surroundings, a decidedly larger percentage of recoveries probably takes place—how much larger cannot be even approximately determined, since, as a rule, only those cases which get well are reported, but few patients come under the care of any single observer, and the chances of error in diagnosis are much greater than in a large general hospital. The mortality rate of the idiopathic cases is very much lower (not exceeding perhaps 25 or 30 per cent.), localized trismus being “never mortal, though it may last for a number of weeks” (Poncet). That recovery should take place much more frequently in cases of this variety than in those associated with wounds might be anticipated, since, as a rule, they are more chronic in their course; the attacks are less frequent; if generalized, the spasms do not involve all the muscles at once, but by progressive seizures and relaxations; and they less often and less severely affect the muscles of respiration. The earlier the disease shows itself after the receipt of a wound (other things being equal), the stronger the likelihood of a fatal termination; and, for obvious reasons, the more powerful, more general, and more quickly repeated the spasms, the greater is the danger. The larger part of the deaths occur within the first week, a majority by the fifth day; all experience tends to show that there was much truth in the Hippocratic observation, that “such persons as are seized with tetanus die within four days, or if they pass these they recover.” From the end of the first week on, the chances of recovery rapidly increase day by day, and after the second week there is but little danger of a fatal termination, though death may take place (from exhaustion usually) after the lapse of several weeks, six or more.11 I have myself seen it occur on the thirty-seventh day.
11 Of the 358 cases reported in the Medical and Surgical History of the War of the Rebellion, the duration of which was known, 64.8 per cent. died within five, and 83.5 per cent. within ten days. Of 327 cases reported by Poland and Hulke, 56 per cent. died within the earlier, and 83.5 per cent. the later, period. Of Richter's cases, 76.6 per cent. died within five days. Of 170 cases tabulated by Yandell, 53 per cent. died within the first four days, and 77 per cent. within nine days.
Recovery is usually slow. Even in the non-traumatic cases the period of convalescence very seldom is less than two months, and, as has been truly said, “it is a very mild case that the patient is well of in thirty days.” More or less stiffness of the muscles usually continues for many weeks; in one case (Currie's) “his features retained the indelible impression of the disease;” and Copland reports having seen a man who had had tetanus nine years before, whose jaws were still permanently locked. Relapses may easily be brought on by exposure or slight imprudences, and such secondary attacks not infrequently prove fatal. The earlier and more severely dysphagic symptoms are manifested, the more grave the prognosis; and the sooner disturbances of respiration are shown, the speedier the death, since spasm of the respiratory muscles, in the words of Aretæus, “readily frees the patient from life.” Generally stated, “the more powerful the contractions, the greater the irritation and the danger;” and the longer the delay of involvement of the respiratory muscles, the more favorable the prognosis. The occurrence of strabismus is of grave import (Wunderlich), as might be expected, since only in very severe cases or in the later hours are the deep muscles of the eye affected by spasm. The manifestation of delirium (which is rare, and sometimes, if not generally, due to over-medication) indicates with almost absolute certainty a speedy death.
The pulse-rate and temperature, especially the latter, afford prognostic indications of value.
A rapid pulse is an unfavorable symptom; and if at the same time it is feeble and irregular, the probabilities of an early death are very great.12 Though, as has already been stated, the temperature often varies but slightly from the normal, even in acute and rapidly fatal cases, yet when the thermometer does not indicate a body-heat of over 100° F. the prognosis is unquestionably more favorable than when it is two or more degrees higher; and there is certainly much truth in the opinion (Arloing and Tripier) that as long as the rectal temperature is not above 1002/5° F. (38° C.) the prognosis is favorable; whereas when it rises the prognosis at once becomes much more grave, few patients recovering in whom it reaches 103° F. Oscillations of temperature are of no prognostic value, good or bad.
12 Few at the present time share Parry's belief, that “if in an adult the pulse by the fourth or fifth day does not reach 100 or perhaps 110 beats in a minute the patient almost always recovers,” and “if, on the other hand, the pulse on the first day is 120 or more in a minute, few instances will be found in which he will not die.”
Death usually occurs suddenly, from spasm of the external respiratory muscles or of those of the larynx, but it may be consequent upon a slow strangulation, upon exhaustion (as it frequently is in the chronic cases), or even upon heart rupture, as in a patient of Dujardin-Beaumetz.
How far the age of the patient affects the prognosis cannot be very definitely stated. The prevalent opinion (entertained as long ago as the time of Aretæus), that the disease is less dangerous in the middle part of life than as either extreme is approached, is probably an erroneous one. Yandell, from the analysis of the cases he had collected, found that the mortality was greatest in children under ten, and least in individuals between ten and twenty years old. Kane's statistics would place the time of greatest danger in the early adult period, from the age of twenty to that of thirty-five or forty.