Document 3eGMQ5d6padz07K5rqMG59XmJ

652 Chapter 36 1945 Guide (2) to remove the great amounts of heat and sometimes moisture, from sterilizing equipment if inside the operating room, from the powerful surgical Tights, from solar heat, and from the bodies, of the operatives, and (3) to provide extra capacity for quickly preparing the room for emergency operations. Much can be gained by-careful insulation of sterilizing equipment' and by thorough exhaust ventilation of sterilizing rooms adjoining the operating rooms. A very common complication presumably traceable to operations is pneumonia. The difference in conditions between the operating room and: the final hospital destination of the patient, including corridors and elevators, is conducive to post-operative pneumonia. A suggested remedy is a recovery ward in which conditions closely approximate those of the operating room and in which the patients remain from one to four days. ` Satisfactory conditions in the recovery ward not only hasten convalescence, but dispel the fear frequently found in patients who must undergo operations during the hot seasons10. Sterilization of Air in Operating Room The. role of light in deterring the spread of respiratory infection is extremely important. Direct sunlight, diffuse daylight from a blue sky and even light which has passed through window glass are all bactericidal in varying degrees11. Hence extensive window space is desirable in operating rooms and hospital wards. The ultra-violet range of the spectrum is the most potent for the sterilization of air. Results reported11 would indicate that the post-operative temperature rise of patients during the first few days is in most instances caused more by bacterial contamination of the operative wound them by the absorption of blood and traumatized tissues. Operating room infections are being reduced subsequent to the installation of special ultra-violet lamps. _ In the use of ultra-violet radiation it is important to use the most efficient part of ,the spectrum with an intensity great enough to render the air relatively sterile and yet not injure tissue for the period of time it will be exposed13. The Council on Physical Therapy of the American Medical Association in a recent action voted acceptance of ultra-violet lamps for disinfecting purposes14. A subcommittee of the Council on Hospital Planning and Plant Operation of the American Hospital Association has recommended that the installation of ultra-violet light equipment should be considered when new contagious disease or surgical operating units are built15. The idea of employing bacterial mists as a method for controlling air borne respiratory infection is not new, but until recently no one has succeeded in producing a sterile or relatively bacteria-free atmosphere by such means which could be tolerated by human beings16. The mists consist of droplets (liquid aerosols) 1 to 2 micra in diameter dispersed in air. Aerosol solutions of sodium hypochlorite (1 gram in 40 million cc of `Report of the Committee on Air Conditioning (The American Hospital Association, p. 2, 1937). ``The Transmission of Certain Infections of Respiratory Origin, by L. Buchbinder (Journal of the American Medical Association 118:718, 1942). `Effect on Wound Healing of Bactericidal Ultraviolet Radiation from a Special Unit-Experimental Study, by Deryl Hart (Archives of Surgery 38:797, 1939). `Considerations in the Use of Ultraviolet Radiation in Operating Rooms, by C. J. Kraissl. J. G. Cimiotti and F. L. Meleney (Annals of Surgery 111:161,1940). 14Acceptance of Ultra-violet Lamps for Disinfecting Purposes, by Council on Physical Therapy (Journal of Ike American Medical Association 118:298, 1942). `Ultra-violet Rays as a Sterilisation Agent in Hospitals, by the Council on Hospital Planning and Plant Operation (American Hospital Association Bulletin No. 203, 1940). ^Bactericidal Action of Propylene Glycol Vapor on Micro-organisms Suspended in Air, by O. H. Robert son Edward- Biggs, Theodore T. Puck and Benjamin F. Miller (Journal of Experimental Medicine 75:593, 1942). -Air,Conditioning-in the-Treatment of Disease ^53 air), a mixture of hexylresorcinal (10 per cent), and an alkysulfate (lorol 0.05 per cent) in alkaline propylene glycol (1 gram of the mixture to 4 billion cc of air) have been reported to sterilize contaminated air samples. Other compounds tested have been either inactive as aerosols or too toxic to be used. Recent work indicates that propylene glycol aerosols in con centrations as low as 1 gram of glycol to 50 million cc of air produce marked and rapid bactericidal effect on atmospheric micro-organisms in droplet form. Atmospheres containing propylene glycol are invisible, odorless and non-irritating. Intensive research in the search for more potent aerosols is in progress. A recent paper17 reports the use of triethy lene glycol mists which prove to be bactericidal in a dilution of 1 gram of glycol to 100 million to 200 million cc of air. Thus far, few data are available on the practical use of germicidal mists and vapors. NURSERIES FOR PREMATURE INFANTS One of the most important requirements in the care of premature infants is the stabilization of body temperature. This is necessary because their heat regulating systems are not fully developed; the metabolism is low and the infants generally exhibit marked inability to maintain normal body temperatures. The resistance to infection is low and mortality rate high. Air Conditioning Requirements The optimum air conditions for the growth and development of these infants were determined by extensive research18 at the Infants Hospital, Boston, Mass., using four valid criteria, namely, stability of body tem perature, gain in weight, incidence of digestive syndromes, and mortality.. Individual temperature requirements varied widely (from 72 to 100 F) according to the constitutional state of the infants and body weights. The optimum relative humidity was about 65 per cent, and the air movement less than 20 fpm. A single nursery conditioned to 77 F and 65 per cent relative humidity was found to fulfill satisfactorily the requirements of the majority of premature infants. Additional heat for weak (or. debilitated) infants may be furnished in the cribs or by means of electric incubators placed inside the conditioned nursery, and the temperature adjusted according to individual requirements. In this way multiplicity of chambers and. of air conditioning apparatus is obviated; the infants in the heated beds derive the benefit of breathing cool humid air, and the nurses and doctors need not expose themselves to extreme conditions. Importance of Humidity: Although external heat is an important factor in the maintenance of normal body temperature, humidity appears to be of equal or greater importance. When the premature nurseries at the Infants 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 humidity 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 of Triethyleni; Glycol Vapor on Air-Borne Bacteria and Influenza Virua, by O. H. Robertson, T. T. Puck. H. F. Lemon and C. G. Loosli (Science 97:142, 1943). rnA!(TttemntRio!!l!ilI't'vADtvy ,of the Effect of Atmospheric Conditions on Growth and on Develop117^' 1933)^ D" BIackfan* C* P. Yaglou and K. McKenzie (American. Journal Diseases of Children, 46: