Disinfection for prevention and control of infections on the threshold of the 21st century for the critically ill patient

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Disinfection for prevention and control of infections on the threshold of the 21

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century for the critically ill patient

Desinfektion zur Vorbeugung und Bekämpfung von Infektionen an der Schwelle des 21. Jahrhunderts beim kritisch Kranken

Abstract

In infectious diseases we can discern a cause and effect chain, which in particular offers the practicable perspectives of prophylaxis and

Franz X. Lackner

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treatment. However, to date we have not been able to control them.

1 Emeritus Clinical Director of the Clinic for Anaesthetics Apart from new epidemics, such as those caused by HIV and SARS,

long-forgotten scourges like TB are enjoying a comeback. Furthermore,

and General Intensive Medi- cine, Vienna, Austria the advances made in clinical medicine mean that induced immunosup-

pression, for instance as a result of major surgery or organ transplant- ation, has become a serious problem in intensive care units. The body’s natural barriers are breached through medical interventions while, on the other hand, immunocompromising therapeutic agents such as cytostacis and glucocorticoids ensure that invading microorganisms will be able to multiply. Drugs administered as stress ulcus prophylaxis give rise to a shift in the bacterial flora of the throat, thus laying the foundation for a lower respiratory tract infection. With regard to bacterial resistance, antibiotic therapy, especially when used as prophylaxis, results in the bacteria becoming less sensitive to the drugs, while rein- forcing selective pressures.

The hands of personnel as well as the therapeutic devices ranging from the respirator to the catheter are the chief sources of infection in intensive care units. Disinfection, antibiotic therapy and, possibly, extracorpo- real elimination methods can be contemplated to selectively prevent the establishment and multiplication of microorganisms. However, only disinfectants are able to unleash their full destructive might against microbes, especially when used for medical devices that are not amenable to sterilization, even if their subsequent removal and, possibly, the issue of staff hand protection, can be a problem. While it is not easy to furnish proof of a direct link between efficient control and prevention methods and the incidence of infection, there is by now a consensus on the role of hand hygiene and of disinfection of the human body and of surfaces. In an age when medicine, in particular intensive care medicine, is at risk of becoming impaled on its own sword, disinfection could serve as a bulwark against rising infection rates.

Zusammenfassung

Bei der Infektionserkrankung bietet sich eine kausale Ursachen-Wir- kungskette dar, welche vor allem praktikable Perspektiven von Prophy- laxe und Therapie einschließt. Dennoch ist es bis heute nicht gelungen, sie zu beherrschen. Neben neuen Epidemien wie die HIV Erkrankung und SARS feiern längst vergessene wie etwa TBC fröhliche Urstände.

Fortschritte der klinischen Medizin haben es zudem mit sich gebracht, dass eine induzierte Immunosuppression etwa durch chirurgische Grosseingriffe und Organtransplantation zum Hauptproblem an der In- tensivstation geworden ist. Von der Natur geschaffene Barrieren werden durch Interventionen überwunden. Demgegenüber stehen Abwehr mindernde Therapeutika wie Zytostatika und Glukokortikoide, welche

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Original Contribution

OPEN ACCESS

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dafür sorgen, dass sich die eingebrachten Keime vermehren können.

Medikamente zur Stressulcusprophylaxe verändern die Keimflora des Rachens und begünstigen damit eine Infektion des unteren Respirati- onstraktes. Von der Resistenz der Keime her bringt die Antibiotikathe- rapie, und zwar vor allem die so genannte Prophylaxe, eine Abnahme der Empfindlichkeit und Selektion mit sich.

Die Hauptinfektionsquellen in Intensivstationen stellen die Hände des Personals sowie Therapiebehelfe vom Respirator bis zum Katheter dar.

Für die direkte Verhinderung der Etablierung und Vermehrung von Mikroorganismen kommen die Desinfektion, die Antibiotikatherapie und eventuell extrakorporale Eliminationsverfahren in Frage. Aber allein die Desifizienzien können mit voller Schärfe ihre Keim vernichtende Kraft entfalten, dies vor allem an nicht sterilisierbaren Therapiebehelfen, wobei nachfolgende Entfernung und gegebenenfalls die Schonung der Hände zum Problem werden können. Wenngleich eine direkte Verbin- dung von effizienten Kontroll- und Verhütungsmaßnahmen mit Infekti- onshäufigkeit schwer bewiesen werden kann, herrscht mittlerweile Ei- nigkeit über die Bedeutung von Handhygiene, Desinfektion am menschlichen Körper und von Oberflächen. Die Desinfektion könnte in Zeiten, in denen die Medizin, speziell die Intensivtherapie, Gefahr läuft, sich in ihren eigenen Fußangeln zu verfangen, ein Anker sein, an dem sich Infektionsraten vor weiterem Ansteigen halten können.

Text

The efforts made to comprehend the essence of disease and its causes have shaped the history of medicine. Even today we are unable to grasp why a particular person suffers from this or that affliction, and despite the advances made in deciphering the genetic code – which in any case explains only how the basic mechanism works, not why – the only recourse left seems to be to place our faith in a higher power. One exception in this unsatisfac- tory situation is infectious disease. Here we can discern a cause and effect chain, which in particular offers the practicable perspectives of prophylaxis and treatment.

Up till the time that Robert Koch discovered more than a hundred years ago that anthrax was caused by a bac- terium, raging epidemics were seen as an expression of God’s curse [1]. While it was possible to control plague and cholera, in addition to new epidemics such as HIV/Aids and SARS long-forgotten scourges like TB are enjoying a comeback.

But such spectacular pathogens account for only part of our problems; the advances made in clinical medicine mean that today not only are we seeing patients with compromised immune systems, who in earlier times would have long succumbed to their underlying disease, but that now such forms of immunosuppression induced, for instance, as a result of major surgery and organ transplants have become a serious problem in intensive care units. This means that it is not only the classic pathogens that are in the spotlight but also a plethora of ubiquitous microorganisms, which as saprophytes have hitherto elicited little attention but are found on all surfaces in a hospital and on the hands of staff.

Bereft of these insights, Ignaz Phillip Semmelweis made the ingenious observation in Vienna during the 19th century that primitive hand disinfection was able to re- duce considerably the incidence of fatal puerperal fever.

Today many of these epidemics and infections have been brought under control, but in intensive care medicine sepsis continues to be the chief nemesis and while we cannot exactly define the situation, an infection is impli- cated in the case of the vast majority of patients who die here, or has indeed been the cause of death.

And here we come upon a fortuitous confluence of all the factors that facilitate microbial invasion of the human body. The body’s natural barriers have been breached through medical interventions, with the common integu- ment sporting myriad large-lumened indwelling catheters, Waldeyer’s tonsilar ring breached by plastic tubes and probes, and even the longer male urethral tract is fitted with a catheter all the more to facilitate retrograde pas- sage of bacteria.

On the other hand, immunocompromising therapeutic agents such as cytostacis and glucocorticoids, which in addition to the inability to ingest nutrition in a natural and efficient manner ensure that invading microorganisms will be able to multiply. Drugs administered as stress ulcus prophylaxis give rise to a shift in the bacterial flora of the throat, thus laying the foundation for a lower respiratory tract infection.

With regard to bacterial resistance, antibiotic therapy, especially when used as prophylaxis, results in the bacteria becoming less sensitive to the drugs, while reinfor- cing selective pressures.

Disinfectants can be deployed not only against all poten- tial microbial reservoirs outside the body, but also on the skin and mucous membranes. In the inanimate environ- ment they can be used with essentially more potent ef-

Lackner: Disinfection for prevention and control of infections ...

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fects than antibiotics, whose use must be governed by considerations of not unduly taxing the body.

The hands of personnel as well as the therapeutic devices ranging from the respirator to the catheter are the chief sources of infection in intensive care units. If one disre- gards the endogenous gut flora and their antibiotic-induced alteration, we can target all microbes giving rise to nosocomial infections with disinfectants before their inoculation.

Disinfection is the cornerstone of any well-organized and hence effective infection control policy. Only recently has a European study reported on the impressive reduction in the incidence of infections brought about by iodine- based products on the skin or at vascular access points as well as by antiseptic hand disinfection [2]. An interna- tional study, which was launched in the USA, underlined the importance of oral decontamination in ventilation pneumonia, which is a key player among the nosocomial infections [3].

Disinfection, antibiotic therapy and possibly extracorpo- real elimination methods can be contemplated for direct prevention of the establishment and multiplication of microorganisms. The latter are still in the incipient stages, while antibiotic treatment represents a double-edged sword since it acts selectively and the entire organism has to be taken into consideration. Only disinfectants are able to unleash their full destructive might against microbes, especially when used on treatment devices that are not amenable to sterilization, but subsequent removal and, possibly, ensuring hand protection, can be a problem.

Much has been written on the difference between cleaning alone and disinfection. Discussions postulate the merits of using quaternary ammonium vs alcohol- based solutions, but what is decisive is optimal use to assure effective infection control tailored to the respective site of use.

An objective evaluation of the suitability of such measures against the background of high costs is possible only through documentation of the clinical effects. Already before the large outcome studies conducted during the past 20 years in the field of intensive care medicine at- tempts were made to analyze infection control on a large scale in central Europe [4]. While it is not easy to furnish proof of a direct link between efficient control and prevention methods and the incidence of infection, there is by now a consensus on the role of hand hygiene and of disinfection of the human body and of surfaces. But an in- ternational study that would be conducted only a decade later was not able to gain any further insights and could only emphatically advocate that European standards be introduced [5].

However, this study spanning 14 countries and more than 1000 intensive care units cast light on the importance of antiseptics. For disinfection of puncture sites before insertion of vascular catheters mainly alcoholic solutions were used; the solution used for the urethral opening was not specified, and most disappointing aspect of this

comprehensive survey was the fact that hand hygiene was assigned only a peripheral role.

In an age when medicine, in particular intensive care medicine, is risking becoming impaled on its own sword, with nosocomial infections being seen as one of the most critical aspects of high tech medicine, disinfection can serve as a bulwark against rising infection rates.

Curriculum Vitae

Univ. Prof. Dr. med. habil. Franz X.

Lackner

Figure 1

Figure 1: Franz X. Lackner

Emeritus Assistant Clinical Director of the Clinic for Anaes- thetics and General Intensive Medicine, Vienna, Austria.

Clinical Investigator and legally sworn expert.

Franz Lackner studied medicine at the University of Vi- enna. He received a doctor’s degree in 1963 and started a specialist training which he finished in 1969 as a specialist for Anaesthetics. Later he moved as Austrian UN- soldier to Cyprus, afterwards to the Albert Einstein College of Medicine, New York. In 1979 he habilitates on the subject of Anaesthetics at the University of Vienna.

But he did not stay there: he became Head of Anaesthet- ics and Intensive Care Department of the Children Hospit- al Modid in Tehran, Iran. After his return he is named Assistant Medical Director of the AHK Vienna and finally Assistant Board Director for the Clinic for Anaesthetics and General Intensive Care Medicine Vienna. He engages himself to a high degree in different ethics committees (Vice Director of the Inter-faculty Institute for Ethics in Medicine, Vice Director of the Ethics Committee of the Vienna Medical Faculty, Chairman of the Ethics committee and Board-member of Eurotransplant Leiden, President of the Austrian Medical Society of Vienna, and member of the Ethics Committee of the Austrian Medical Associ- ation).

He took on emeritus status as a professor in 2000.

References

1. Man versus microbe [Editorial]. Nat med. 2004;10(12Suppl):S69.

2. Misset B et al. Continuous quality improvement program reduces nosocomial infection in the ICU. Intensive Care Med.

2004;30:395-400.

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3. Kollef M. Ventilator associated pneumonia. Crit Care Med.

2004;32(6):1396-405.

4. Benzer H, Brühl P, Dietzel W, Kilian J, Lackner F, Reybrouck G, Rotter M, Werner G. The hygienic situation in 56 German, 33 Austrian and 25 Belgian Intensive Care Units. Infect Control.

1987;8(9):376-9.

5. Moro M, Jepsen O. Infection control practices in intensive care units of 14 European countries. Intensive Care Med.

1996;22:872-9.

Corresponding author:

Univ. Prof. Dr. Franz X. Lackner

Lichtensteinstraße 11, A-2345 Brunn/Gebirge franz.lackner@univie.ac.at

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Lackner FX. Disinfection for prevention and control of infections on the threshold of the 21^stcentury for the critically ill patient . GMS Krankenhaushyg Interdiszip. 2007;2(1):Doc12.

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