Disinfection for infection prevention over the course of time.

In recent years and decades increasingly more emphasis has been placed on alcohol-based solutions for hygienic and surgical hand disinfection. Traditional handwashing with soap and water has been largely replaced in the everyday clinical setting, as has the use of disinfectant soap-based solutions for surgical hand disinfection. It has been possible in recent years to reduce the exposure time for alcohol-based hand disinfection in surgery from 5 to 3 minutes, and there are plans to reduce this even further. The growing awareness of the tolerability issues has also given rise to favorable developments here. There have also been dramatic changes in preoperative skin disinfection. The non-alcoholic solutions with a slow onset of action (e.g. iodophors) have been virtually replaced by alcohol-based solutions of demonstrated efficacy. Non-alcoholic solutions continue to be used for disinfection of mucous membranes, but iodine-based products are being phased out here. The term "instrument disinfection" has been largely supplanted now by the expression "instrument reprocessing or medical device decontamination" (which is also underpinned by legislation) and it takes account of the trend towards thermal disinfection. Meticulous cleaning is thus an indispensable precondition for sterilization, which normally follows disinfection. The greatest lack of consensus at European level relates to surface disinfection. Routine, parallel cleaning and disinfection of all surfaces close to and remote from the patient is being increasingly replaced by selective disinfection, whenever warranted, of surfaces close to the patient. The problem here is that medical personnel continue to view cleaning and disinfection as interchangeable tasks. This situation is further compounded by the fact that hospitals are finding it increasingly more difficult to assure adequately successful cleaning and disinfection outcomes. To ensure effective infection control, cleaning and disinfection of surfaces in special situations must also be assured whenever warranted outside the regular working hours. Disinfection and decontamination of highly complex medical devices that pose special challenges (heat-sensitive devices with an intricate design and, correspondingly, with surfaces that are difficult to access, e.g. flexible endoscopes) will present the main challenge in the future. There is still much to be accomplished here to assure the hygienic safety of the patient.

[PC-based computer monitoring in an intensive care unit]. / Computerüberwachung auf PC-Basis für eine Intensivstation.

The lack of direct communication with the intensive care patient means the medical staff have to try to achieve a realistic picture of the condition of the patient from numerous pieces of detailed information fitted together something like a jigsaw. The immense amount of data thus gained means an overall interpretation of the many individual data would be hardly imaginable without the use of a computer. PC networks in conjunction with a high-level language provide an ideal basis for building up a background monitoring system that can be used at the bedside. Simple PC-ATs and software developed in house in Turbo-Pascal have enabled us to realize a useful and very economical computer-aided background monitoring system. Any online and offline data important for an operative critical care unit can be collected, documented, displayed and processed in secondary parameters.

[The choice of the method of anesthesia as a risk factor in the femoral fracture near the hip joint in elderly patients]. / Wahl der Anaesthesiemethode als Risikofaktor bei der hüftgelenknahen Oberschenkelfraktur des alten Patienten.

Between January 1983 and December 1988, 317 patients with fractures near the hip joint were operated upon. In a retrospective study we compared 180 patients with general anesthesia (AN) and 137 patients with spinal anesthesia (RA). The average age of patients with RA was 80.5 and with AN 79.8 years. The preoperative management was done by an internist. The operation followed at an average of 2.8 days (Tables 1, 2). All patients were placed into 3 risk groups, based on after preoperative cardiac and pulmonary risk scores, as modified by Goldman (Table 3). Spinal anesthesia was performed with 2 ml 4% hyperbaric mepivacaine (80 mg mepivacaine hydrochloride, 190 mg glucose monohydrate). The AN was induced with thiopental (3-5 mg/kg) and maintained with N2O and enflurane. Fentanyl (0.05-0.15 mg) was given for analgesia. The statistical examination was done using the chi-square test (Fisher-exact or Pearson). The groups were compared for age, time of operation, and risk score (Table 4). The mortality in operations with protection of the femoral head (FP) (Ender pinnings, Böhler pinnings and dynamic hip screws) was significantly higher after RA (13.8%), than with AN (6.5%). In operations with hip prostheses (HP), the mortality for RA (19.0%) was also significantly higher then for AN (4.2%) (Fig. 1). The mortality in group I (4-20 points) was 1.7% in patients with AN (FP 1.4%, HP 2.1%) and 3.7% for RA (FP 4.1%, HP 0%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Monitoring infection at the intensive care unit--a multicenter pilot study]. / Infektionsüberwachung an Intensivstationen--eine multizentrische Pilotstudie.

During a period of 3 months an infection survey was carried out in 4 intensive care units (ICUs), 2 in Vienna, Austria, and one each in Ulm and Münster, Federal Republic of Germany, using a common protocol. A total of 329 patients was monitored prospectively. This pilot study was performed to evaluate the usefulness of parameters included in the monitoring form. It was attempted to characterize the patient populations of the four units. Mean duration of stay (1-12 days), mortality (8-26%), leading diagnosis upon admission, intubation rate (41-91%) and use of pulmonary artery catheter (12-35%) were distinctly different. The rate of patients admitted already with an infection was 9-43%, septicemia was diagnosed in up to 27% of the diseased. The rate of infection acquired in the unit was between 12 and 37%, the most frequent types were bronchopneumonia, septicemia and urinary tract infection. When septicemia patients were compared to non-septicemia patients who had been admitted for more than 3 days, it appeared that the latter stayed significantly shorter at the ICU and showed less frequently bronchopneumonia or urinary tract infection at the time of admission. Septicemia patients acquired more frequently additional infections like broncho-pneumonia or urinary tract infection while staying at the ICU. The median day of onset of septicemia was the fifth day and only in a quarter of cases diagnosis could be supported by a positive blood culture. The use of antibiotics in the 4 ICUs is compared and shows marked differences. Based upon experience with this type of infection survey a new modified protocol is introduced, which displays the time course of documented events.

[Application of an infection control protocol at an anesthesiology intensive care unit]. / Anwendung eines Infektionsüberwachungsprotokolles auf einer anaesthesiologischen Intensivstation.

We studied the efficiency and practicability of a new protocol for surveillance of nosocomial infection in 99 patients admitted to our intensive care unit (ICU) between October 1985 and March 1986. The protocol contained the therapy given before admission to the ICU and daily records of: (1) therapy suspected to increase the risk of nosocomial infection (ventilatory support, operations, hemofiltration, central venous and arterial catheters, Swan-Ganz catheters, etc.); (2) parameters possibly associated with bacterial infections (white blood cell count, body temperature, platelet count, creatinine clearance, hemodynamic values, clinical suspicion of infection, suspected site of infection, pathological chest X-ray, etc); and (3) bacteriologic data (results of cultures from blood, tracheal aspirate, urine, wound secretions) and antibiotic treatment. Sepsis was diagnosed in 28 patients, and 28 had positive blood cultures; these two groups were not identical. Twenty-nine patients died, more than half of them having a serious nosocomial infection. Factors associated with nosocomial infection were: fever greater than 38.5 degrees C, recurrent fever, leucocytosis, leucopenia, thrombocytopenia; duration of stay at the ICU; ventilatory support, operations, mass transfusions, and therapy with catecholamines. Use of a Swan-Ganz catheter and hemofiltration were associated with nosocomial infection, but they were usually begun after the clinical onset of sepsis. Therapy administered before admission to the ICU was not associated with nosocomial infection. Bacterial colonization of tracheal aspirate was detected in 2/3 of the ventilated patients. The most common bacteria isolated were staphylococci in blood cultures. Pseudomonas sp. and Candida albicans in tracheal secretions, and Candida albicans in urine cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

Tonic descending inhibition affects intensity coding of nociceptive responses of spinal dorsal horn neurones in the cat.

The supraspinal inhibitory control of lumbar spinal dorsal horn neurones was investigated in N2O-anaesthetized cats by reversibly blocking conduction in the spinal cord. Dorsal horn neurones selected for this study had convergent input from myelinated (A-) and unmyelinated (C-) fibres in the posterior tibial and/or superficial peroneal nerves of the hind limb. Virtually all of them could also be excited by noxious heating of the skin of the footpad region and by low intensity mechanical stimulation of the foot. Variation of the temperature of noxious radiant skin heating (40-56 degrees C, 10 sec in duration) resulted in graded responses of the neurones. The stimulus-response functions (SRF) were monotonic; in the majority of 32 cases they were linear. Neurones could be classified according to their maximum discharge frequency in response to skin heating into 22 weakly sensitive units (responses below 100 Hz at 50 degrees C) and 10 highly sensitive units (above 100 Hz). Responses outlasted the period of skin heating by seconds to minutes. A reversible conduction block of spinal axons by cooling a 15 mm cord segment (L1) with a thermode at 0 degrees C affected the responsiveness of the dorsal horn neurones in 12 of 15 cases. The maximum discharge frequency to a certain temperature of skin heating was increased during the spinal block. The duration of heat-evoked discharges was either not changed or increased during the spinal block. The SRF were reversibly displaced during the spinal blockade to higher discharge frequencies and lower threshold temperatures of skin heating. In 8 of 12 cases the change in the SRF was a nearly parallel shift, whereas in 4 units the increase of responsiveness had a complex effect upon the SRF. The decrease in the threshold to skin heating ranged up to 4.5 degrees C; the mean decrease was 2 degrees C. It is confirmed that in anaesthetized cats, nociceptive spinal neurones are subject to a tonically active descending inhibition, which is interrupted by local spinal cooling. The effect of the spinal block on the SRF of the neurones suggests that this tonic inhibition is similar to that produced by electrical stimulation in the lateral reticular formation of the brain-stem.

[Positive modification of hemodynamics in post cardiac surgery patients by hemofiltration. Improved method for the demonstration of myocardial depressant factor (MDF) in hemofiltrate]. / Positive Beeinflussung der Hämodynamik bei postkardiochirurgischen Patienten durch die Hämofiltration. Eine verbesserte Methodik zur Darstellung des Myocardial Depressant Factor's (MDF) in Hämofiltrat.

The method of haemofiltration was used in 29 postoperative cardio-surgical patients with low blood pressure, high left ventricular filling pressure and low total peripheral resistance, which did not respond to the use of the intraaortic balloon pump or pharmaco-therapy. In severe low-output syndrome hemodynamic parameters are: reduced mean arterial pressure, increased left ventricular filling pressure, increased mean arterial pulmonary pressure as well as significantly reduced total peripheral resistance [4-6, 28]. Inspite of pharmaco-therapy, cardiac performance regarding peripheral perfusion is insufficient; this leads to a vicious cycle of irreversible O2-debt and severe cellular damage. After haemofiltration there was a significant improvement in the haemodynamic parameters, which in our opinion was due to the elimination of toxic peptides such as Myocardial Depressant Factor (MDF). In 27 of a total of 29 patients, haemodynamic parameters returned to normal after treatment. 19 patients were discharged, eight patients died after a number of days or weeks from causes not related to the original cardiogenic shock (cerebral embolism, reinfarction, myocardiopathy and pneumonia).

[Continuous arteriovenous hemofiltration in interstitial pulmonary edema]. / Kontinuierliche arteriovenöse Hämofiltration beim interstitiellen Lungenödem.

In a retrospective study 40 ICU patients, all underwent Continuous Arteriovenous Hemofiltration (CAVH) for acute pulmonary, acute renal insufficiency or both, were evaluated for lung function parameters and fluid balance. It could be shown that a group of patients suffering from pulmonary insufficiency and with a history of major trauma or obstetric complications mainly benefits from fluid control by means of CAVH, while diuretics were unable to perform the desired action.

[Control of infection in a primarily surgical intensive care unit]. / Infektionsüberwachung an einer vorwiegend chirurgischen Intensivbehandlungsstation.

All of one year's 251 patients of a predominantly surgical intensive care unit (i.c.u.) were continuously followed up for infections according to a standard protocol. These protocols were evaluated for 174 patients who stayed at least 48 h at the unit. More than one third (36.7%) were already infected on admission (external origin), 35% contracted infections at the unit, primarily or additionally (internal origin) and 40% remained without an infection. Fifty eight percent of patients already infected on admission were surgical and required intensive care for complications. Among the patients who contracted their infection solely at the unit 61.5% suffered from trauma. Patients having contracted their infections at the i.c.u. stayed significantly longer than those without (additional) infections (13 and 6 days respectively). Mortality was highest (45%) in patients who were already infected on admission and who acquired additional infections during their stay at the i.c.u. Of patients with infections of exclusively external or internal origin 23.5 and 17.9% respectively died whereas among those who remained uninfected this proportion was only 7%. The 75 infections acquired before admission to the i.c.u. included infections of the respiratory tract in 14.4% of all patients, peritonitis with 10.3%, urinary tract in 8.0% and septicemia in 5.2%. Artificial ventilation was employed more often in infected patients (73.8-100%) than in non-infected ones (56.3%). They also carried more intravasal catheters (2.76-3.05 per patient) than the latter group (1.79). Of the 82 infections acquired in the i.c.u. the respiratory tract was affected in 19.5% of all patients and the urinary tract in 13.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative application of high-frequency ventilation.

High-frequency pulsation (HFP), a modified high-frequency jet ventilation (HFJV) technique, was applied intraoperatively as an alternative to conventional inter mittent positive-pressure ventilation in 16 patients undergoing major thoracic operations. Gas exchange and hemodynamic stability were maintained at a frequency of 300 cycle/min. Surgical maneuvers were easier because the lungs were almost completely immobilized.

[Intensive medicine--and what follows? Psychosocial follow-up study of former intensive care patients]. / Die Intensivmedizin--und was ist danach? Psychosoziale Nachuntersuchung ehemaliger Intensivpatienten.

Intensive care medicine enables the organic survival of many seriously ill patients; however, long continuing of disease and trauma itself and the addition of life supporting therapy can remain and make social readjustment difficult. In order to obtain data on the outcome of former intensive care patients we re-examined all patients for three consecutive years who had been discharged from a multidisciplinary ICU. The patients and relatives were interviewed to elucidate changes in personality, behaviour and handicaps. These data were tested on the basis of several hypotheses. 182 patients were tested. The death rate varied for the three different years between 27% up to 37% per reexamined year. 22%-32% of the former patients reported being seriously, 69%-78% reported being moderately disabled. The suicidal tendency is equal to the standard population, although dying and death become a central theme (39%). Due to the drug consumption the health status got worse in 35% of the former patients. Despite severe psychological and physical handicaps 97% were convinced of the necessity of an ICU.

[A model for standardized treatment and therapeutic evaluation of severe ARDS. PIF and AaDO2 quotient with a demand-adapting respirator and a conventional respirator during ARDS]. / Ein Modell zur einheitlichen Behandlung und Therapieauswertung beim schweren ARDS. PIF und AaDO2 Quotient bei bedarfsadaptierter Beatmung mit konventionellen Beatmungsgeräten im Verlauf eines ARDS.

In order to achieve a uniform, easy to teach and to manage respiratory management in severe adult respiratory distress syndrome (ARDS) a combined treatment--called "step by step scheme"--was settled. It was aimed towards a regulation of the arterial blood oxygen tension at levels between 90 and 130 mmHg and this was achieved by combination of PEEP and IRV in order to minimize the inspiratory fraction of oxygen. Nine patients underwent this schedule and Benzer's AaDO2 quotient as an estimation of lung function as well as PIF (PEEP X I:E X FiO2) as quantifying parameter for the "strength" of the respirator are calculated. AaDO2 Quotient showed no statistically significant differences but PIF performed a clearly marked day of maximum respiratory support during the clinical course. This seems to be a confirmation that a variable defined by therapeutic procedures may also be an estimation of a certain degree of sickness as a pure diagnostic parameter. In plotting AaDO2 quotient versus PIF characteristically formed loops result. These loops give some evidence about the interactions between improving or worsening ARDS and properly adjusted therapeutic efforts by means of a respirator. The diagram may be also helpful in deciding conventional respirator settings or weaning procedures and show marks, where one might consider to treat by new techniques like High Frequency Ventilation, extracorporeal devices or arteriovenous hemofiltration.

[Effect of arm splinting on the duration and possibility of monitoring invasive long-term pressure determination of the radial artery]. / Einfluss der Armschienung auf Verweildauer und Monitierbarkeit bei blutiger arterieller Langzeitdruckmessung über die A. radialis.

A special splint technique, which can improve continuous intraarterial blood pressure monitoring via the a. radialis is reported. This method could be applied successfully in 41 patients of the ICU up to 27 days. Cannulating the contralateral side because of catheter's dysfunction was necessary only in 6 patients. These observations could be seen in contrast to our results, using a conventional splint system, applied in 12 patients for comparison (maximal duration of catheter's placement: 9 days). Our experiences, using this special splint method of arm fixation, lead to the recommendation to use our method routinely in long-term monitored patients, with respect to a longer duration of catheter's intravasal placement, the possibility of undisturbed monitoring and a simple clinical handling.

[Psychological stress factors in intensive care]. / Psychische Stressfaktoren in der Intensivmedizin.

In three intensive care units we looked into the question whether there are environmental situations somewhat equally stressful for the patients using 52 stress items designed by ourselves for the study. The patients had to place the various items in a sequence of increasing annoyance just one day after discharge from the intensive care unit. The most annoying factor for all patients, almost independent of sex and diagnosis, was the item "lack of information and communication". The item "noise and unrest caused by the daily routine and the nursing staff of the intensive care unit" was put in the first place by patients aged more than 50 years. Helplessness and physical impairment are the most annoying factors reported by the ventilated patients. The item "dependence on technical devices" (e.g. ventilators, dialyzer etc.) was surprisingly quoted low by our patients. We conclude that a human orientated intensive care medicine approach should be developed. Further investigations concerning psychical care and help should be performed.

[Inversed ratio ventilation (IRV) following cardiosurgical procedures]. / Inversed Ratio Ventilation (IRV) nach kardiochirurgischen Eingriffen.

Based on our positive experiences with "Inversed Ratio Ventilation" (IRV) in the treatment of ARDS, we applied this ventilation technique in patients with risk lungs after cardiosurgical operations. Immediately, after switching from conventional ventilation mode (I/E ratio 1:2) to IRV (I/E 2:1), however significant hemodynamic reactions could be observed. Especially a significant decrease of cardiac output can be observed in this phase. IRV leads to an improvement of gas exchange and lung mechanics. These improvement become even more significant continuing IRV. A decreasing tendency of the negative hemodynamic effects can be observed parallel to lung mechanics improvement. Carefully managed respirators adjustment, "step-wise" prolongation of I/E ratio and closed observation on hemodynamic reactions leads to successful use of Inversed Ratio Ventilation in cardiosurgical patients too.