On hyperpyretic conditions during infancy and childhood.: A clinical study of fever.
Authors: ÅKERRÉN Y. 
Published: January 2008

Summary.The author gives an account of a series of 232 cases of illness in children (0–12 years old), who, on at least one occasion, exhibited a temperature of at least 41.0°C. The most commonly recorded cause of fever was acute and severe affection of the air passages in the form of pneumonia, bronchopneumonia and capillary bronchitis. Meningites (tuberculous und purulent) were also relatively numerously represented. The cases have been divided into three groups. Group 1 (121 individuals) comprises cases in which, apart from the acute fever condition, the patient exhibited no provable morbid condition, and in whom the acute infection had not its site or essential focus in the brain or meninges; group 2 (34 individuals), cases where acute severe meningitic or cerebral or closely allied morbid conditions were present; and group 3 (77 individuals) patients in whom more or less far‐reaching somatic or psychic morbid conditions, or defects independent of the acute fever condition, were present. The treatment of the material, inter alia, has given the following results:

Prognosis: The total mortality amounts to 129 (= 56%). Group 2 has the worst prognosis, with 33 deaths out of 34 (= 97%), next follows group 3 with 52 deaths out of 77 (67.5 ± 5.3%), and finally group 1, with 44 deaths out of 121 (36.4 ± 4.4%). Within group 1 there is a statistically verified higher mortality for the ages under 2 years in comparison with ages above 2 years. A comparison between the mortality within groups 1 and 3 in the ages below 2 years, shows good agreement from the statistical point of view between the groups, and this also holds good for the ages under 1 year in the same groups. The difference in the prognosis between groups 1 and 3 is thus entirely due to the fact that the higher ages are considerably more numerously represented in group 1 than in group 3.
There is a special disposition to fall ill with hyperpyretic fever among children who are suffering from more or less grave somatic or psychic morbid conditions or defects. (For the rest see the casuistics and discussion on p. 6 and 13).
It is possible that there is a greater disposition to fall ill with hyperpyretic fever before the age of 2 years, but no definite conclusion can be drawn as to this from the present material.
In the cases ending fatally the last temperature taken was the highest in 79.8 ± 3.5% of the cases. Within groups 1 and 3 together the corresponding frequency was 77.1 ± 4.3%. In a statistically verified majority of the cases the terminal temperature was the highest in groups 1 and 3 together. A study of a control material of cases of fever conditions ending fatally in children who did not exhibit a hyperpyretic fever during the fatal illness, shows that in these cases there was no dominating tendency towards terminal rises in temperature. In this series the highest temperature observed in a statistically verified majority among the cases was not the last one before death, but an earlier one.
Within groups 1 and 3 it proves that, among the survivors, the median for the highest temperature measured is 41.1°, while among those who died it is 41.5°. Among the survivors the frequency of a maximum temperature of at most 41.2° was statistically higher than among the dead. On the other hand, the frequency of temperatures of at least 42.0° was considerably higher among the dead than among the survivors. The highest temperature measured in some of the survivors was 42.3°, in the dead 43.3°.
There is not only a close time connection (cf. point 4 above), but also in all probability a causal connection between the hyperpyrexia and death. Above all, the remarkable circumstance that the prognosis for children under 2 years within group 1 exhibits good statistical agreement with the prognosis for children of the same age within group 3, shows that the hyperpyrexia will probably be of great importance in connection with the onset of death. For if this special factor did not exercise a decisive influence, the prognosis should be considerably better in group 1 than in group 3 where—apart from the acute fever or infection condition—morbid conditions or defects, in themselves likely considerably to disimprove the prognosis in cases of acute infection illnesses, were present in all the cases. The observations in point 5 as to the connection between the height of the maximum temperature measured and the prognosis quo ad vitam also point in the same direction.
The outcome of a discussion of the pathogenesis of hyperpyrexia is, inter alia, that the following factors are of importance: a) circulation disturbances, especially in the skin, b) disturbances in the central thermoregulation, and c) insufficient attention to the conditions for the physical thermoregulation conducted via the skin in the matter of clothing, room temperature, fluid supply, etc.
In cases of hyperpyretic temperatures, there is a fairly common and typical symptom complex, which is characterized by disturbances in consciousness, frequently coma, general flaccidity of the muscles, possibly alternating with convulsions, great pallor of the skin, and hurrid, sometimes heavy or racing respiration, and weak, rapid pulse, implying an imminent menace to life. The designation the hyperpyretic syndrome is suggested for this symptom complex.
Certain of the acute, menacing, often fatal, conditions, which in the cases ending fatally are called “deaths from eczema”, are an example of the hyperpyretic syndrome. With these conditions an all too vigorous and thorough‐going treatment with salves and bandages and insufficient attention to the physical thermoregulation conditions, will often be of importance. The condition of pallor and hyperpyrexia (“Syndrome de pâleur‐hyperthérmie”, Ombeédanne) met with after operative measures on infants and small children, is also an example of the hyperpyretic syndrome.
The primary object of the therapy in the case of the fully developed hyperpyretic syndrome is to reduce the temperature as promptly as possible. Judging from clinical experience, however, this is often very difficult, or impossible, and, inter alia, the time during which the hyperpyrexia has been present will probably be of importance. Some favourable cases of the fully developed hyperpyretic syndrome are described. More important than the therapy, however, is the prophylaxis, which consists, inter alia, of careful temperature control, especially in younger children who are suffering from acute infections or eczema, or who have recently been operated on. In these cases every tendency towards a sudden rise in temperature, especially if it approaches the hyperpyretic temperatures, must be combated, inter alia, by attention to the thermoregulation conditions (clothing, room temperature, fluid supply), and possibly also with the help of hydrotherapy and antipyretics. The risk of overheating in fever conditions, when possibly hyperpyrexia is the result of a combined effect of an endogenous fever condition and treatment injuries (unsuitable, too closely fitting, and too warm clothing, etc.), should be carefully watched in infants and small children.