Evaluation of the practice of reprocessing ORs in German hospitals from an infection prevention and control perspective.

BACKGROUND: The aim of this study was to analyze the cleaning and disinfection of operating rooms (ORs) status quo focusing on hygiene plans in German hospitals. METHODS: In 2016, a structured online survey was sent to infection prevention and control (IPC) specialists at the cost calculation hospitals of the Institute for the Hospital Remuneration System (InEK) and all university hospitals in Germany (n = 365). RESULTS: With a response rate of 27.4%, 78% stated that written hygiene plans were available. After cleaning and disinfecting an OR with a "septic" patient, 55% waited until surfaces were dry before reusing in accordance with national recommendations, 27% waited > 30 min. Additionally, 28% of hospitals had ORs only for "septic" patients. In 56% "septic" patients were only operated on at the end of the program. Postoperative monitoring of patients with bacteria with special IPC requirements took place in the post anesthesia care unit (PACU) (29%), operating room (OR) (52%), intensive care unit (ICU) (53%), and in the intermediate care unit (IMC) (19%). DISCUSSION AND CONCLUSIONS: Despite written hygiene plans in place the partly long duration of OR nonuse time following IPC measures, the consistent continued use of stratification for "septic" patients and the postoperative follow-up care of patients with colonizing/infecting bacteria with special IPC requirements in the OR and high care areas represent relevant potential for improvement.

Case delay in the OR morning start in hospitals of different size and academic status : Results from a German multicenter study to identify incidence and causes of delayed anesthesia ready time.

BACKGROUND: Delays in the start of morning operations cause a loss of expensive OR capacity as well as frustration and potential conflicts among the different professions involved. There are a lot of reasons which can lead to delayed anesthesia ready time (ART). This is the first large multicenter study to identify incidence, extent and reasons of delay in ART. METHODS: First case delays in ART were studied in all regular ORs in 36 hospitals of different sizes (smaller community hospitals, larger community hospitals and university hospitals) over a period of 2 weeks. We analyzed the results comparing the 3 hospital types regarding incidence, extent and reasons for delay. RESULTS: A total of 3628 first of day cases were included in the study. Incidences of delayed ART (delay >5 min) ranged from 26.5% in university hospitals to 40.8% in larger community hospitals. However, university hospitals had higher incidences than smaller community hospitals of delays greater than 15 and 30 min. The main reasons for delays were prolonged induction of anesthesia, patient in-hospital logistics and delayed patient arrival at the hospitals. The highest mean delay of delayed cases was found in university hospitals with 21.7 min ± 14.7 min (SD). CONCLUSIONS: Delays in anesthesia ready time have a high prevalence in most hospitals, however the reasons for delay are manifold, making interventions to reduce delay complex.

[Does hospital volume correlate with surgical process time? : Retrospective analysis of the five most common procedures for visceral surgery, trauma and orthopedic surgery and gynecology/obstetrics from the benchmarking program of the Berufsverband Deutscher Anästhesisten (BDA), Berufsverband Deutscher Chirurgen (BDC) and Verband für OP-Management (VOPM)]. / Korreliert die Leistungsmenge eines Krankenhauses mit der chirurgischen Prozesszeit? : Retrospektive Analyse der jeweils fünf häufigsten Prozeduren aus den Bereichen Viszeralchirurgie, Unfall­/orthopädische Chirurgie und Gynäkologie/Geburtshilfe aus dem Benchmarking-Programm von BDA, BDC und VOPM.

BACKGROUND: Minimum volume thresholds for specific surgical procedures in German hospitals were established in 2004 but remain controversial. For the first time, this study investigated the relationship between hospital performance volume and surgical procedure duration in a multicenter approach. The question here was whether a concentration on frequently performed procedures leads to a reduction in surgical process times. METHODS: In a retrospective analysis, the 5 most common procedures from visceral, trauma/orthopedic and gynecological/obstetrics surgery were examined in hospitals participating in a benchmarking program. For each procedure performed between 2013 and 2015, hospitals were divided into 4 groups depending on the hospital volume provided. The average surgical duration of incision to suture time was calculated between the group with "very low" hospital volume and the other three groups ("low", "high" and "very high"). RESULTS: OR cases from 75 hospitals were analyzed. The number of included cases per procedure ranged from 31,940 to 2705. The average number of operations performed in a specific procedure was 3-4 times higher in high-volume hospitals compared to very low-volume hospitals. A linear relationship between hospital volume and surgical process time only appeared to be clearly seen in laparoscopic cholecystectomy, appendectomy and arthroscopic meniscus surgery: a higher case load led to a reduction in incision to suture time. For the other procedures, the surgical process times were inconsistent between the hospital groups. CONCLUSION: The case volume only appeared to have a direct but limited influence on incision to suture times in laparoscopic and arthroscopic procedures. Overall, the hospital performance volume appeared to be of subordinate importance in terms of OR-economics.

Epidemiology and outcomes of Clostridium difficile infection in allogeneic hematopoietic cell and lung transplant recipients.

BACKGROUND: Clostridium difficile infection (CDI) is a common complication of lung and allogeneic hematopoietic cell (HCT) transplant, but the epidemiology and outcomes of CDI after transplant are poorly described. METHODS: We performed a prospective, multicenter study of CDI within 365 days post-allogeneic HCT or lung transplantation. Data were collected via patient interviews and medical chart review. Participants were followed weekly in the 12 weeks post-transplant and while hospitalized and contacted monthly up to 18 months post-transplantation. RESULTS: Six sites participated in the study with 614 total participants; 4 enrolled allogeneic HCT (385 participants) and 5 enrolled lung transplant recipients (229 participants). One hundred and fifty CDI cases occurred within 1 year of transplantation; the incidence among lung transplant recipients was 13.1% and among allogeneic HCTs was 31.2%. Median time to CDI was significantly shorter among allogeneic HCT than lung transplant recipients (27 days vs 90 days; P = .037). CDI was associated with significantly higher mortality from 31 to 180 days post-index date among the allogeneic HCT recipients (Hazard ratio [HR] = 1.80; P = .007). There was a trend towards increased mortality among lung transplant recipients from 120 to 180 days post-index date (HR = 4.7, P = .09). CONCLUSIONS: The epidemiology and outcomes of CDI vary by transplant population; surveillance for CDI should continue beyond the immediate post-transplant period.

Fluorescent markers of various organelles in the wheat pathogen Zymoseptoria tritici.

Development of novel strategies to control fungal plant pathogens requires understanding of their cellular organisation and biology. Live cell imaging of fluorescent organelle markers has provided valuable insight into various aspects of their cell biology, including invasion strategies in plant pathogenic fungi. Here, we introduce a set of 17 vectors that encode fluorescent markers to visualize the plasma membrane, endoplasmic reticulum (ER), chromosomes, the actin cytoskeleton, peroxisomes and autophagosomes in the wheat pathogen Zymoseptoria tritici. We fused either enhanced green-fluorescent protein (eGFP) or a codon-optimised version of GFP (ZtGFP) to homologues of a plasma membrane-located Sso1-like syntaxin, an ER signalling and retention peptide, a histone H1 homologue, the LifeAct actin-binding peptide, a mitochondrial acetyl-CoA dehydrogenase, a peroxisomal import signal and a homologue of the ubiquitin-like autophagosomal protein Atg8. We expressed these markers in wildtype strain IPO323 and confirmed the specificity of these markers by counterstaining or physiological experiments. This new set of molecular tools will help understanding the cell biology of the wheat pathogen Z. tritici.

Effects of functional endoscopic sinus surgery on the acoustics of the sinonasal tract.

BACKGROUND: Nasal and paranasal cavities are supposed to contribute substantially to the vocal tract resonator properties. However, their acoustical effects as well as the effects of sinus surgery on the voice remain unclear. In this work we investigate resonance phenomena of paranasal sinuses prior to and after various rhinosurgical procedures in cadaveric human sinonasal tracts and corresponding 3D casts. METHODOLOGY: Nasal and paranasal cavities of formalin-preserved cadavers and corresponding 3D replicas were excited by sine-tone sweeps from an earphone placed in the epipharynx. The response was picked up by a microphone at the nostrils. Different FESS procedures were performed and the acoustical responses following excitation were recorded. The measured acoustical changes in the obtained transfer functions were then evaluated. RESULTS: Marked low frequency dips were detected in the transfer functions when sinus cavities were included in the nasal resonator system. These dips showed a significant correlation with sinus volumes. Following FESS procedures they moved upwards in frequency depending on the extent of the surgical intervention. CONCLUSIONS: The transfer functions obtained in cadaveric situs and 3D replicas showed dips at the resonance frequencies of the paranasal cavities. Marked acoustic effects in terms of increase in dip frequency following FESS procedures were reproducibly documented.

[Palliative therapy concepts in intensive care medicine]. / Palliative Therapiekonzepte in der Intensivmedizin.

Involvement of palliative care is so far not common practice for critically ill patients on surgical intensive care units (ICUs) in Germany. The objectives of palliative care concepts are improvement of patient quality of life by relief of disease-related symptoms using an interdisciplinary approach and support of patients and their relatives considering their current physical, psychological, social and spiritual needs. The need for palliative care can be identified via defined screening criteria. Integration of palliative care can either be realized using a consultative model which focusses on involvement of palliative care consultants or an integrative model which embeds palliative care principles into the routine daily practice by the ICU team. Early integration of palliative care in terms of advance care planning (ACP) can lead to an increase in goals of care discussions and quality of life as well as a decrease of mortality and length of stay on the ICU. Moreover, stress reactions of relatives and ICU staff can be reduced and higher satisfaction with therapy can be achieved. The core of goal of care discussions is professional and well-structured communication between patients, relatives and staff. Consideration of palliative care principles by model-based integration into ICU practice can improve complex intensive care courses of disease in a productive but dignified way without neglecting curative attempts.

[Relevance of preoperative anxiety for postoperative outcome in urological surgery patients: A prospective observational study]. / Bedeutung präoperativer Angst für den postoperativen Verlauf bei urologischen Patienten : Eine prospektive Beobachtungsstudie.

BACKGROUND: Preoperative anxiety is not systematically assessed during premedication appointments, although it may influence the postoperative course and outcome. OBJECTIVES: The aim of this study was to assess preoperative anxiety in a sample of patients before major urological surgery and to characterize the impact on postoperative pain. An additional aim was to analyze the agreement between patients' self-ratings and physicians' anxiety ratings. PATIENTS AND METHODS: In all, 127 male and 27 female patients participated in a prospective observational study. Preoperative anxiety was assessed with two validated instruments - the APAIS (Amsterdam Preoperative Anxiety and Information Scale) and the State Scale of the STOA questionnaire (State-Trait Operation Anxiety) - during the premedication appointment. Physicians provided their subjective ratings on patients' anxiety and need for information using the APAIS. The predictive value of preoperative anxiety for postoperative pain was evaluated. RESULTS: Nearly four out of ten patients were identified as "anxiety cases"; thereof women were more afraid than men were. Preoperative anxiety was not correctly assessed by physicians, who overestimated patients' anxiety. In female patients, preoperative anxiety was predictive of increased postoperative pain scores. CONCLUSION: Preoperative anxiety is a frequent concern and often not correctly assessed by physicians. The use of scoring systems to detect preoperative anxiety is useful in clinical routine and helps to decide on therapeutic interventions.

[Optical diagnostic methods for early tumour diagnosis in the upper aerodigestive tract: Quo vadis?]. / Optische Diagnoseverfahren zur Tumorfrühdiagnostik im oberen Luft-Speise-Weg: Quo vadis?

BACKGROUND: Optical diagnostic methods may simplify and improve the early diagnosis of tumours of the upper aerodigestive tract; however, these have not yet found their way into clinical routine. OBJECTIVE: This article aims to define the problems that have prevented routine use of optical diagnostic methods so far, as well as listing and also explaining potential trendsetting approaches to overcome these difficulties. MATERIALS AND METHODS: The study is based on a combined analysis of publically accessible databases (PubMed MEDLINE, Thompson Reuters Web of Science, SPIE. Digital Library; full time period available; search strings: "oral cavity", "pharynx", "larnyx", "optical diagnosis", "optical biopsy", "optical coherence tomography", "confocal endomicroscopy", "fluorescence endoscopy", "narrow band imaging", "non-linear imaging", "fluorescence lifetime imaging"), as well as personal experiences. RESULTS: Both conceptual and methodical problems were determined, and possible solutions based on current developments are discussed. CONCLUSION: Optical diagnostic methods have the potential to revolutionise early diagnosis of upper aerodigestive tract malignancies, providing the different hurdles listed in this review can be overcome.

[Speech Ability and Psychological Outcome After Treatment of Oral Cancer]. / Sprechqualität und psychische Beeinträchtigung nach der Therapie von Mundhöhlentumoren.

BACKGROUND: In recent years interactions between surgical treatment of oral carcinoma and incidence of anxiety or depression have become a subject of discussions. This prospective study is a comparison between the extent of loss of speech intelligibility and presence of depressive symptoms or anxiety as a result of oral carcinoma. MATERIAL AND METHODS: One year after surgical therapy for oral carcinoma, 90 patients of an average age of 60±12 years were examined. Their speech intelligibility degree was measured using standardized automatic speech recognition (word recognition rate, WR). Symptoms of anxiety and depression were detected by use of HAD-Scales (HADS). Next to the relationship between WR and HADS other influential variables related to WR and HADS were statistically evaluated. RESULTS: The WR average was 53.2±17.2. Female WR was better than male. The difference between tumor classifications T1 and T4 compared to the WR reached statistical significance. Significant differences were detected between WR and "tumor localization", "graft donor site", "graft morphology", "tongue motility", and "tracheostoma" groups. There was a relationship between tongue motility and graft morphology, graft donor site and tumor localization. HAD-Scores in the mean were elevated: HADS-Total=43.3%, HADS-A=43.3% und HADS-D= 51.1%. WR correlates with HADS-D-Subscale, but not with HADS-A-Subscale. CONCLUSION: Communication disorders as a result of neoplasmic orofacial surgery may be related to extent of the treatment and to affective impairments. This should receive attention in the concept of rehabilitation.

Fluorescent markers of the microtubule cytoskeleton in Zymoseptoria tritici.

The microtubule cytoskeleton supports vital processes in fungal cells, including hyphal growth and mitosis. Consequently, it is a target for fungicides, such as benomyl. The use of fluorescent fusion proteins to illuminate microtubules and microtubule-associated proteins has led to a break-through in our understanding of their dynamics and function in fungal cells. Here, we introduce fluorescent markers to visualize microtubules and accessory proteins in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein to α-tubulin (ZtTub2), to ZtPeb1, a homologue of the mammalian plus-end binding protein EB1, and to ZtGrc1, a component of the minus-end located γ-tubulin ring complex, involved in the nucleation of microtubules. In vivo observation confirms the localization and dynamic behaviour of all three markers. These marker proteins are useful tools for understanding the organization and importance of the microtubule cytoskeleton in Z. tritici.

Fluorescent markers of the endocytic pathway in Zymoseptoria tritici.

Hyphal growth in filamentous fungi is supported by the uptake (endocytosis) and recycling of membranes and associated proteins at the growing tip. An increasing body of published evidence in various fungi demonstrates that this process is of essential importance for fungal growth and pathogenicity. Here, we introduce fluorescent markers to visualize the endocytic pathway in the wheat pathogen Zymoseptoria tritici. We fused enhanced green-fluorescent protein (eGFP) to the actin-binding protein fimbrin (ZtFim1), which is located in actin patches that are formed at the plasma membrane and are participating in endocytic uptake at the cell surface. In addition, we tagged early endosomes by eGFP-labelling a Rab5-homologue (ZtRab5) and late endosomes and vacuoles by expressing eGFP-Rab7 homologue (ZtRab7). Using fluorescent dyes and live cell imaging we confirmed the dynamic behavior and localization of these markers. This set of molecular tools enables an in-depth phenotypic analysis of Z. tritici mutant strains thereby supporting new strategies towards the goal of controlling wheat against Z. tritici.

Conditional promoters for analysis of essential genes in Zymoseptoria tritici.

Development of new fungicides, needed for sustainable control of fungal plant pathogens, requires identification of novel anti-fungal targets. Essential fungal-specific proteins are good candidates, but due to their importance, gene deletion mutants are not viable. Consequently, their cellular role often remains elusive. This hindrance can be overcome by the use of conditional mutants, where expression is controlled by an inducible/repressible promoter. Here, we introduce 5 inducible/repressible promoter systems to study essential genes in the wheat pathogen Zymoseptoria tritici. We fused the gene for enhanced green-fluorescent protein (egfp) to the promoter region of Z. tritici nitrate reductase (Pnar1; induced by nitrogen and repressed by ammonium), 1,4-ß-endoxylanase A (Pex1A; induced by xylose and repressed by maltodextrin), l-arabinofuranosidase B (PlaraB; induced by arabinose and repressed by glucose), galactose-1-phosphate uridylyltransferase 7 (Pgal7; induced by galactose and repressed by glucose) and isocitrate lyase (Picl1; induced by sodium acetate and repressed by glucose). This was followed by quantitative analysis of cytoplasmic reporter fluorescence under induced and repressed conditions. We show that Pnar1, PlaraB and Pex1A drive very little or no egfp expression when repressed, but induce moderate protein production when induced. In contrast, Pgal7 and Picl1 show considerable egfp expression when repressed, and were strongly induced in the presence of their inducers. Normalising the expression levels of all promoters to that of the α-tubulin promoter Ptub2 revealed that PlaraB was the weakest promoter (∼20% of Ptub2), whereas Picl1 strongly expressed the reporter (∼250% of Ptub2). The use of these tools promises a better understanding of essential genes, which will help developing novel control strategies that protect wheat from Z. tritici.

Fluorescent markers for the Spitzenkörper and exocytosis in Zymoseptoria tritici.

Fungal hyphae are highly polarized cells that invade their substrate by tip growth. In plant pathogenic fungi, hyphal growth is essential for host invasion. This makes polarity factors and secretion regulators potential new targets for novel fungicides. Polarization requires delivery of secretory vesicles to the apical Spitzenkörper, followed by polarized exocytosis at the expanding cell tip. Here, we introduce fluorescent markers to visualize the apical Spitzenkörper and the apical site of exocytosis in hyphae of the wheat pathogen Zymoseptoria tritici. We fused green fluorescent protein to the small GTPase ZtSec4, the myosin light chain ZtMlc1 and the small GTPase ZtRab11 and co-localize the fusion proteins with the dye FM4-64 in the hyphal apex, suggesting that the markers label the hyphal Spitzenkörper in Z. tritici. In addition, we localize GFP-fusions to the exocyst protein ZtExo70, the polarisome protein ZtSpa2. Consistent with results in the ascomycete Neurospora crassa, these markers did localize near the plasma membrane at the hyphal tip and only partially co-localize with FM4-64. Thus, these fluorescent markers are useful molecular tools that allow phenotypic analysis of mutants in Z. tritici. These tools will help develop new avenues of research in our quest to control STB infection in wheat.

Red fluorescent proteins for imaging Zymoseptoria tritici during invasion of wheat.

The use of fluorescent proteins (FPs) in plant pathogenic fungi provides valuable insight into their intracellular dynamics, cell organization and invasion mechanisms. Compared with green-fluorescent proteins, their red-fluorescent "cousins" show generally lower fluorescent signal intensity and increased photo-bleaching. However, the combined usage of red and green fluorescent proteins allows powerful insight in co-localization studies. Efficient signal detection requires a bright red-fluorescent protein (RFP), combined with a suitable corresponding filter set. We provide a set of four vectors, suitable for yeast recombination-based cloning that carries mRFP, TagRFP, mCherry and tdTomato. These vectors confer carboxin resistance after targeted single-copy integration into the sdi1 locus of Zymoseptoria tritici. Expression of the RFPs does not affect virulence of this wheat pathogen. We tested all four RFPs in combination with four epi-fluorescence filter sets and in confocal laser scanning microscopy, both in and ex planta. Our data reveal that mCherry is the RFP of choice for investigation in Z. tritici, showing highest signal intensity in epi-fluorescence, when used with a Cy3 filter set, and laser scanning confocal microscopy. However, mCherry bleached significantly faster than mRFP, which favors this red tag in long-term observation experiments. Finally, we used dual-color imaging of eGFP and mCherry expressing wild-type strains in planta and show that pycnidia are formed by single strains. This demonstrates the strength of this method in tracking the course of Z. tritici infection in wheat.

A codon-optimized green fluorescent protein for live cell imaging in Zymoseptoria tritici.

Fluorescent proteins (FPs) are powerful tools to investigate intracellular dynamics and protein localization. Cytoplasmic expression of FPs in fungal pathogens allows greater insight into invasion strategies and the host-pathogen interaction. Detection of their fluorescent signal depends on the right combination of microscopic setup and signal brightness. Slow rates of photo-bleaching are pivotal for in vivo observation of FPs over longer periods of time. Here, we test green-fluorescent proteins, including Aequorea coerulescens GFP (AcGFP), enhanced GFP (eGFP) from Aequorea victoria and a novel Zymoseptoria tritici codon-optimized eGFP (ZtGFP), for their usage in conventional and laser-enhanced epi-fluorescence, and confocal laser-scanning microscopy. We show that eGFP, expressed cytoplasmically in Z. tritici, is significantly brighter and more photo-stable than AcGFP. The codon-optimized ZtGFP performed even better than eGFP, showing significantly slower bleaching and a 20-30% further increase in signal intensity. Heterologous expression of all GFP variants did not affect pathogenicity of Z. tritici. Our data establish ZtGFP as the GFP of choice to investigate intracellular protein dynamics in Z. tritici, but also infection stages of this wheat pathogen inside host tissue.

A gene locus for targeted ectopic gene integration in Zymoseptoria tritici.

Understanding the cellular organization and biology of fungal pathogens requires accurate methods for genomic integration of mutant alleles or fluorescent fusion-protein constructs. In Zymoseptoria tritici, this can be achieved by integrating of plasmid DNA randomly into the genome of this wheat pathogen. However, untargeted ectopic integration carries the risk of unwanted side effects, such as altered gene expression, due to targeting regulatory elements, or gene disruption following integration into protein-coding regions of the genome. Here, we establish the succinate dehydrogenase (sdi1) locus as a single "soft-landing" site for targeted ectopic integration of genetic constructs by using a carboxin-resistant sdi1(R) allele, carrying the point-mutation H267L. We use various green and red fluorescent fusion constructs and show that 97% of all transformants integrate correctly into the sdi1 locus as single copies. We also demonstrate that such integration does not affect the pathogenicity of Z. tritici, and thus the sdi1 locus is a useful tool for virulence analysis in genetically modified Z. tritici strains. Furthermore, we have developed a vector which facilitates yeast recombination cloning and thus allows assembly of multiple overlapping DNA fragments in a single cloning step for high throughput vector and strain generation.

[Improving Structures for Healthy and Self-Determined Ageing in an Urban District]. / Quartiersstrukturen für Gesundheit und Selbstbestimmung im höheren Lebensalter verbessern.

Between 2007 and 2010 the Institut für Gerontologische Forschung e.V. investigated the "Primary Prevention Effects of the Märkisches Viertel Network" in the Berlin district "Märkisches Viertel". The study integrates, amongst others, various participatory methods to investigate the health promotion effects of the volunteer Märkisches Viertel Network, an organisation that brings together different local actors working to assist and encourage older people to live independent lives. Sustained active collaboration by a heterogeneous mixture of actors in a spatially defined quarter, engagement by the local housing association, and increasing acknowledgement of and participation by older residents were identified as success factors for a change in local structures.

[How many patient transfer rooms are necessary for my OR suite? : Effect of the number of OR transfer rooms on waiting times and patient throughput in the OR - analysis by simulation]. / Wie viele Patientenschleusen braucht mein OP-Bereich? : Einfluss der Zahl von OP-Schleusen auf Wartezeiten und Patientendurchsatz im OP - Analyse mithilfe einer Simulation.

INTRODUCTION: In most hospitals the operating rooms (OR) are separated from the rest of the hospital by transfer rooms where patients have to pass through for reasons of hygiene. In the OR transfer room patients are placed on the OR table before surgery and returned to the hospital bed after surgery. It could happen that the number of patients who need to pass through a transfer room at a certain point in time exceed the number of available transfer rooms. As a result the transfer rooms become a bottleneck where patients have to wait and which, in turn, may lead to delays in the OR suite. In this study the ability of a discrete event simulation to analyze the effect of the duration of surgery and the number of ORs on the number of OR transfer rooms needed was investigated. METHODS: This study was based on a discrete event simulation model developed with the simulation software AnyLogic®. The model studied the effects of the number of OR transfer rooms on the processes in an OR suite of a community hospital by varying the number of ORs from one to eight and using different surgical portfolios. Probability distributions for the process duration of induction, surgery and recovery and transfer room processes were calculated on the basis of real data from the community hospital studied. Furthermore, using a generic simulation model the effect of the average duration of surgery on the number of OR transfer rooms needed was examined. RESULTS: The discrete event simulation model enabled the analysis of both quantitative as well as qualitative changes in the OR process and setting. Key performance indicators of the simulation model were patient throughput per day, the probability of waiting and duration of waiting time in front of OR transfer rooms. In the case of a community hospital with 1 transfer room the average proportion of patients waiting before entering the OR was 17.9 % ± 9.7 % with 3 ORs, 37.6 % ± 9.7 % with 5 ORs and 62.9 % ± 9.1 % with 8 ORs. The average waiting time of patients in the setting with 3 ORs was 3.1 ± 2.7 min, with 5 ORs 5.0 ± 5.8 min and with 8 ORs 11.5 ± 12.5 min. Based on this study the community hospital needs a second transfer room starting from 4 ORs so that there is no bottleneck for the subsequent OR processes. The average patient throughput in a setting with 4 ORs increased significantly by 0.3 patients per day when a second transfer room is available. The generic model showed a strong effect of the average duration of surgery on the number of transfer rooms needed. CONCLUSION: There was no linear correlation between the number of transfer rooms and the number of ORs. The shorter the average duration of surgery, the earlier an additional transfer room is required. Thus, hospitals with shorter duration of surgery and fewer ORs may need the same or more transfer rooms than a hospital with longer duration of surgery and more ORs. However, with respect to an economic analysis, the costs and benefits of installing additional OR transfer rooms need to be calculated using the profit margins of the specific hospital.