[What Surgeons Should Know about Risk Management]. / Risikomanagement in der Chirurgie ­ was muss der Chirurg wissen?

Background: The fact that medical treatment is associated with errors has long been recognized. Based on the principle of "first do no harm", numerous efforts have since been made to prevent such errors or limit their impact. However, recent statistics show that these measures do not sufficiently prevent grave mistakes with serious consequences. Preventable mistakes such as wrong patient or wrong site surgery still frequently occur in error statistics. Methods: Based on insight from research on human error, in due consideration of recent legislative regulations in Germany, the authors give an overview of the clinical risk management tools needed to identify risks in surgery, analyse their causes, and determine adequate measures to manage those risks depending on their relevance. The use and limitations of critical incident reporting systems (CIRS), safety checklists and crisis resource management (CRM) are highlighted. Also the rationale for IT systems to support the risk management process is addressed. Results/Conclusion: No single tool of risk management can be effective as a standalone instrument, but unfolds its effect only when embedded in a superordinate risk management system, which integrates tailor-made elements to increase patient safety into the workflows of each organisation. Competence in choosing adequate tools, effective IT systems to support the risk management process as well as leadership and commitment to constructive handling of human error are crucial components to establish a safety culture in surgery.

[Neuromuscular deficits in chronic ankle instability. Frequency and significance - multicenter study]. / Neuromuskuläres Defizit bei chronischer Sprunggelenkinstabilität. Häufigkeit und Wertigkeit - Multicenterstudie.

The peroneal reaction time (PRT) is used in the assessment of neuromuscular deficits in chronic functional ankle instability. Powered by the Editorial Manager and Preprint Manager from Aries Systems Corporation the present study was conducted to determine the PRT in a large collective of patients with chronic ankle instability because it is unclear if this parameter of neuromuscular deficit is prolonged. In this study 186 patients underwent a diagnostic algorithm consisting of anamnesis, clinical examination, X-ray and determination of the PRT on a tilting platform. A prolonged PRT as a manifestation of a neuromuscular deficit could be detected in the majority of the patients (n = 143, 77%). Comparing the affected and healthy legs 77 patients (41%) showed a significant difference in talar shift (p = 0.002) and talar tilt (p = 0.04) in the radiological stress views. Of these 77 patients only 15 (8%) showed radiological evidence of a mechanical problem. As a consequence of recurring ankle sprains a post-traumatic deficit in proprioception has to be expected in most cases. In general a conservative therapy approach should be followed including specific training to improve neuromuscular and proprioceptive deficits.

[Clinical relevance of a routinely performed magnetic resonance cholangiopancreatography (MRCP) prior to cholecystectomy]. / Klinische Wertigkeit einer routinemäßigen Magnetresonanz-Cholangiopankreatikografie (MRCP) vor Cholezystektomie.

BACKGROUND: A preoperative diagnostic imaging procedure is essential for therapy in cholecystolithiasis. According to the S3-Guidelines of the German Society for General and Visceral Surgery only an ultrasound scan is needed before a cholecystectomy. But an anatomic variant of the bile ducts or choledocholithiasis is poorly shown by an ultrasound. Because of this, we performed a magnetic resonance cholangiopancreatography (MRCP) routinely. This study was designed to show if the MRCP changed the treatment plan or changed the operation method. Furthermore, the sensitivity and specificity concerning abnormalities of the cystic duct, accessory bile ducts and choledocholithiasis should be determined. PATIENTS AND METHODS: During the time between January 1st 2005 and September 30th 2009 541 patients were included in this retrospective study. RESULTS: Among the 541 cases 98 pathologies were found. These included 51 choledocholithiasis, 20 accessory bile ducts and 13 abnormal cystic ducts. In 29 of the 51 cases of choledocholithiasis a therapeutic splitting was performed only because of the MRCP. In 22 cases the diagnosis was also possible because of the basic diagnostic procedures like ultrasound, laboratory tests and clinical appearance. So the diagnostic aimprovement due to the MRCP is 5.3 %. Four of the 20 accessory bile ducts and 6 of the abnormal cystic ducts were found during the subsequent operation. The sensitivity concerning the anatomic variants is very low (38.5 % concerning the accessory bile ducts and 50 % for the abnormal cystic ducts). But the sensitivity in detecting a choledocholithiasis is very high (94.7 %). There was no evidence in our study that MRCP prevented any complications. The operation method was not changed in any case because of the MRCP result. CONCLUSION: A routinely performed preoperative MRCP cannot be recommended.

Critical limb ischaemia: initial treatment and predictors of amputation-free survival.

OBJECTIVES: To evaluate initial treatment and risk factors for amputation-free survival in patients with critical limb ischaemia (CLI). DESIGN: Prospective clinical cohort study at a single vascular surgical centre in Germany. METHODS: Data on 104 consecutive patients (115 ischaemic limbs) presenting with their first episode of CLI were collected prospectively over a 3-year period. Initial treatment was classified as conservative therapy, intervention, surgery, or major amputation. Patient co-morbidities were assessed by uni- and multivariate analysis to determine risk factors for limb salvage, survival and amputation-free survival. RESULTS: Indications for treatment were rest pain in 27 (23.5%) and tissue loss in 88 (76.5%) limbs. Revascularisation was attempted in 65% of all limbs: 45% by intervention and 55% by surgery. In 9% primary amputation was necessary and 22% received conservative therapy. Median follow-up was 28 months (1-42). The 3-year limb salvage, patient survival, and amputation-free survival rates were 73%, 41%, and 31%, respectively. Diabetes, cardiac disease and renal insufficiency were associated with poor survival. Combined cardiac and renal disease adversely affected amputation-free survival (HR, 3.68; 95% CI, 1.51-8.94; P < 0.001). CONCLUSIONS: At least two third of all patients presenting with CLI can be offered some type of direct revascularisation. In patients with major cardiac disease and renal insufficiency, a poor outcome in terms of amputation-free survival is to be anticipated.

[Patient assessments of quality of life following bypass for chronic critical limb ischaemia]. / Bypass bei chronisch kritischer Extremitätenischämie. Lohnt sich die Mühe aus Sicht des Patienten?

The value of infrainguinal bypass surgery for critical limb ischaemia (CLI) in elderly patients is being scrutinised more as medical resources decline. Despite technically successful revascularisation, patient quality of life seems impaired by delayed wound healing and repeated hospitalisation for interventions and operations. Therefore it is questionable whether these frail patients benefit from bypass surgery with respect to their health-related quality of life. This review examines current evidence of patients with CLI and summarises the effect of bypass surgery on their own quality of life assessments. All in all, patients benefit from the revascularisation because ambulation status improves and independence is preserved. From a patient's perspective these improvements in quality of life justify an aggressive approach towards revascularisation for CLI.

[Removal of a thoracic impaling agent without direct observation. The significance of pre-operative diagnosis]. / Entfernung eines thorakalen Pfählungsgegenstandes ohne direkte Sicht. Die Bedeutung der präoperativen Diagnostik.

Impalement injuries are uncommon and only occasional reports exist in the literature, resulting in non standardized approaches. Depending on the location, completely different combinations of injuries occur, making every impalement unique. Nevertheless some basic principles for dealing with impalements exist. These principles, and some controversial statements in the literature on the value of preoperative diagnostics, especially CT, are discussed using the example of a spectacular thoracic impalement by a 2 x 2 cm square metal pole. Our deviation from the principal of removing an impaling object only under direct observation in this special case is also discussed.

Oxygen saturation course and altitude symptomatology during an expedition to broad peak (8047 m).

Thirteen healthy European mountaineers (11 male, 2 female) participated in the 62-day German-Pakistani Research Expedition to Broad Peak (8047 m) in the Karakorum, Pakistan. During ascent, base camp stay and approach to the summit, oxygen saturation was measured by pulse oximetry at rest, during exercise and during sleep; in addition, questionnaires on high altitude symptomatic had to be answered. We found a dramatic decrease in oxygen saturation especially at extreme altitudes (7100 m: Median 63%, Min 59%, Max 65%) and a long time required for real acclimatization. The lowest figures at 4850 m were found during maximal exercise, 77.5% (69 - 85%) and during sleep, 81% (73 - 88%), the highest ones at rest, 86.5% (77 - 89%). There was a significant correlation (Spearman rank correlation coefficient with ties) between measured oxygen saturation during the ascent to/stay at base camp and high altitude illness (p = 0.005 - 0.05), as well as with high altitude performance (p = 0.025 - 0.01). The limiting values of "no high altitude symptomatic", "high altitude discomfort", AMS and the malignant forms could be estimated for acclimatized (>90%/>80%/>70%/<70%) and unacclimatized (>80%/>70%/>65%/<65%) condition. Pulse oximetry is an objective non-invasive method of measurement that is easy to handle. It is a suitable device besides clinical examination and questionnaire-test in the diagnosis of high altitude illness even in the hands of non-professionals. The measurement at sleep can possibly explain present high altitude symptomatic despite of (nearly) normal oxygen saturation values at rest.

[Peroneal reaction time: study of a normal sample]. / Die peroneale Reaktionszeit: Untersuchung in einem Normalkollektiv.

Chronic functional instability is a residual problem after acute ankle sprain. Reasons may be weak ligaments and/or a deficit in the proprioceptive system. Studies have shown that peroneal reaction time (PRT) can be used to quantify proprioceptive performance. To test the influence of anthropometric data on PRT, an experimental study with 120 healthy volunteers was performed. Surface electrodes recorded the activity of the peroneal muscles after a sudden inversion on a tilting platform. It was found that PRT is not influenced by extrinsic or anthropometric data. Furthermore, the results prove a significant slackening in PRT with increasing age. Therefore, the patient's age must to be considered in judging the PRT.

Regulation of extracellular matrix synthesis by mechanical stress.

The extracellular matrix (ECM) provides mechanical support to tissues and is a substrate for cell adhesion and differentiation. Cells bind to ECM via specific cell surface receptors such as integrins. When engaging with ECM ligands, these receptors can activate signal transduction pathways within the cells and may act as mechanochemical transducers. Thus, interaction of cells with ECM can modulate gene expression although the exact mechanisms are not known. Among the genes that are, in part, controlled by cell-ECM interactions are those for certain ECM components themselves. Bone cells, for example, remodel their matrix and reorient bone trabeculae in response to mechanical strain. Recently, we found that fibroblasts attached to a strained collagen matrix produce more of the ECM glycoproteins tenascin and collagen XII than cells in a relaxed matrix. In vivo, these two proteins are specifically expressed in places where mechanical strain is high. We also showed that the chick tenascin gene promoter contains a novel cis-acting, "strain-responsive" element that causes enhanced transcription in cells attached to a strained collagen matrix. Similar enhancer elements might be present in the promoters of other genes induced by mechanical stress. It can be speculated that connective tissue cells sense force vectors in their ECM environment and react to altered mechanical needs by regulating the transcription of specific ECM genes; this process is a prerequisite for matrix remodeling.

Tenascin-C expression by fibroblasts is elevated in stressed collagen gels.

Chick embryo fibroblasts cultured on a collagen matrix exert tractional forces leading to the contraction of unrestrained, floating collagen gels and to the development of tension in attached, restrained gels. On a restrained, attached collagen gel the fibroblasts synthesize large quantities of tenascin-C, whereas in a floating, contracting gel tenascin-C synthesis is decreased. This regulation of tenascin-C synthesis can be observed by the secretion of metabolically labeled tenascin-C into the conditioned medium, as well as by the deposition of tenascin-C into the collagen matrix as judged by immunofluorescence. Regulation appears to occur at the transcriptional level, because when cells on attached or floating collagen gels are transfected with promoter constructs of the tenascin-C gene, luciferase expression driven by the tenascin-C promoter parallels the effects measured for endogenous tenascin-C synthesis, whereas luciferase expression under the control of the SV40 promoter does not depend on the state of the collagen gel. The promoter region responsible for tenascin-C induction on attached collagen gels is distinct from the region important for the induction of tenascin-C by serum, and may define a novel kind of response element. By joining this tenascin-C sequence to the SV40 promoter of a reporter plasmid, its activity can be transferred to the heterologous promoter. We propose that the tenascin-C promoter is directly or indirectly activated in fibroblasts generating and experiencing mechanical stress within a restrained collagen matrix. This may be an important aspect of the regulation of tenascin-C expression during embryogenesis as well as during wound healing and other regenerative and morphogenetic processes.

Identification of the murine cytomegalovirus glycoprotein B gene and its expression by recombinant vaccinia virus.

The gene encoding glycoprotein B (gB) of murine cytomegalovirus (MCMV) strain Smith was identified, sequenced, and expressed by recombinant vaccinia virus. The gB gene was found adjacent to the polymerase gene, as it is in the genome of human cytomegalovirus (HCMV). The open reading frame consists of 2,784 nucleotides capable of encoding a protein of 928 amino acids. Comparison with gB homologs of other herpesviruses revealed a high degree of homology. The similarity between the MCMV gB and the HCMV gB is most prominent, since 45% of the amino acids are identical. In addition, all cysteine residues are at homologous positions, indicating a similar tertiary structure of the two proteins. In contrast to HCMV, the MCMV gB mRNA is a true late transcript. A recombinant vaccinia virus expressing the MCMV gB gene has been constructed (Vac-gB). Antibodies raised against the Vac-gB recombinant precipitated proteins of 130, 105, and 52 kDa from MCMV-infected cells. The identity of the MCMV gB with the major envelope glycoprotein of MCMV described by Loh et al. was shown (L. C. Loh, N. Balachandran, and L. F. Qualtiere, Virology 166:206-216, 1988). Immunization of mice with the Vac-gB recombinant gave rise to neutralizing antibodies.