Document 2RG0B0pN3nN5x7007DkOEQ28a

224 CHAPTER. 13 1948 Guide to be of equal or greater importance.: When, the premature nurseries at the Children's Hospital were kept at relative humidity between 25 and 50 per cent for two weeks or longer, the body temperature became unstable, gain in weight diminished, the incidence of gastro-intestinal disturbances increased, and the mortality rose. On the other hand, continuous exposure to air conditions with 55 to 65 per cent relative Ktcmidity gave satisfactory results over a period of years. The initial physiologic loss of body weight (loss occurring within first four days of life) was found to vary inversely with the humidity. In the oldnurseries, with natural humidity it averaged 12.4 per cent of the birth weight; in the conditioned nurseries it was 8.9 per cent with:25 to 49 per cent relative humidity, and 6.0 per cent with 50 to 75 per cent relative humidity.; The number of days required to regain the. birth weight was correspondingly maximum in the old nursery and minimum in the conditioned nurseries under high humidity; v Maximum gains in body weight occurred, in the conditioned nurseries under high humidity (55 to 65 per cent) in infants .weighing less than 5 lb. . The gains were less under low humidity (25 to 50 per cent) in the same nurseries, and in the old nurseries prior to. the installation of air conditioning apparatus: The incidence and severity of digestive' syndromes, with diarrhea, persistent vomiting, diminishing gain ;or. loss.of body weight, and other symptoms, were generally from two to three times as high Under low as under high humidity. Summarizing, the best chances for life in premature infants are created by maintaining a relative humidity of 65 per cent in the n.ursery and by providing a uniform environmental temperature just sufficiently high to keep the body temperature within normal limits. Medical and nursing care are, of course, factors of equal and sometimes' of greater importance: Air Conditioning Equipment Many of the installations now in use are of the central system type providing for filtration, for humidification and heating in cold weather, and for cooling and dehumidification in hot weather. A ventilation rate, between 8 and 12 air changes, is desirable to remove odors and maintain uniformity of temperatures in extremes of weather. Recirculation should hot be used in these wards owing to odors and the possibility of infection. There should be a frequent change in spray water. Control of Airborne Infection The protectibn of the premature and older- infant against infection is of the utmost importance. It was found in one installation equipped with air conditioning, germicidal lights and mechanical barriers that air conditioning- alone did not prevent the spread of respiratory cross infections. Bactericidal ultraviolet light barriers and air conditioning or mechanical barriers and air conditioning were efficient21. FEVER THERAPY Artificial production of fever in man is an imitation of nature's way of overcoming invading pathogenic organisms. The action may be direct and specific, by destruction of the invading. organism within the safe limit of human temperatures, or indirect in the.case of, heat resistant Air Conditioning in the Prevention and Treatment of Disease 225 organisms,, by general mobilization of the defensive mechanisms of the body, which retard or neutralize the activity of pathogenic bacteria and their toxins. ' ' Although'the action may be direct and specific by destruction of the invading organisms within the safe human limits, fever therapy exerts much of its benefit through the improvement of the mechanism of bodily defense. A serious challenge to the theory on which fever therapy is based comes from the demonstration that high fever causes a reduction in the concentration of circulating antibodies in experimental animals. Clinically, it has been shown that there is no change in the per cent of phagocytes which engulf bacteria in patients during fever therapy, although the action of the complement fixing . antibodies may be temporarily diminished. Patients for fever therapy should be. carefully selected. The most serious complications which may arise are heat stroke, heat exhaustion and circulatory collapse. The chief minor, complications are spasm, heat cramps, fever blisters and mild dehydration. .. The limits of induced systemic fever are usually between 104 and 107 F . (rectal), and the duration from 3 to 8 hours at a time. The total period of fever treatment varies with the type of the organism involved from a few hours to 50 or more. The diseases which, respond favorably to artificial fever therapy are gonorrhea and its complications (which include arthritis, pelvic infections . in women, and involvement of the eye),'syphilis, chorea, infectious _arthritis (non-gpnorrheal), encephalitis, and some forms of asthma. There; are other conditions which show promise under- this treatment; but the most'striking results are seen in gonorrhea and syphilis, since the causative organisms can be destroyed at temperatures compatible-with human life. Equipment for Production of Fever Artificial fever can be induced by injections of various crystalloid or colloid substances, bacterial products of typhoid and malarial.organisms, or by physical methods using hot baths, radiant heat -cabinets, hot humidified air cabinets, -or by short wave diathermy in combination with; a cabinet. ... The relative advantages of various methods have: been evaluated clinically 2?. Among the devices for the production of fever by physical means, `the one: most widely used is the hot humid air or'air conditioned, cabinet. This apparatus was developed at the Kettering 'Institute for Medical Research at Miami Valley Hospital in'Dayton,1 Ohio.- In the earlier studies of the Society, temperatures were elevated more . easily using saturated atmospheres. A fever therapy apparatus 23 rusing these same principles has proved efficient as a means of inducing and maintaining fever in a body with small likelihood of burns because of the comparatively low dry-bulb temperatures. When heat is necessary in treating legs or arms, such media as short or long wave diathermy, infrared, water baths, etc. have been used extensively: A recent development, a saturated atmosphere heating unit, similar to one previously described has proven satisfactory, because heat may be administered over longer periods which render deep heating possible without fear of bums or shocks. Local heating has been some what satisfactory in relieving the painful symptoms of-peripheral vascular disease. Some investigators employ short wave diathermy, within the