Preoperative patient assessment: Identifying patients at high risk.

Postoperative mortality remains alarmingly high with a mortality rate ranging between 0.4% and 4%. A small subgroup of multimorbid and/or elderly patients undergoing different surgical procedures naturally confers the highest risk of complications and perioperative death. Therefore, preoperative assessment should identify these high-risk patients and stratify them to individualized monitoring and treatment throughout all phases of perioperative care. A "tailored" perioperative approach might help further reduce perioperative morbidity and mortality. This article aims to elucidate individual morbidity-specific risks. It further suggests approaches to detect patients at the risk of perioperative complications.

[Perioperative risk and mortality after major surgery]. / Perioperatives Risiko und Letalität nach großen chirurgischen Eingriffen.

Although anesthesia-associated mortality has been significantly reduced down to 0.00068-0.00082% over the last decades, recent studies have revealed a high perioperative mortality of 0.8- 4%. Apart from anesthesia and surgery-induced major complications, perioperative mortality is primarily negatively influenced by individual patient comorbidities. These risk factors predispose for acute critical incidents (e.g., myocardial infarction); however, the majority of fatal complications are a result of slowly progressing conditions, particularly infections or the sequelae of systemic inflammation. This implicates a broad window of opportunity for the detection and treatment of slow-onset complications to improve the perioperative outcome. The term "failure to rescue" (FTR), i.e., the proportion of patients who die from major complications compared to the number of all patients with complications, has been introduced as a valid indicator for the quality of perioperative care. Growing evidence has already shown that FTR is an underestimated factor in perioperative medicine accounting for or at least being involved in the development of postoperative mortality. While the incidence of severe postoperative complications amazingly does not show much variation between hospitals, FTR shows significant differences implying a major potential for improvement. With 14 million surgical procedures per year in Germany, a postoperative mortality of approximately 1% and an avoidable FTR rate of 40% mean that there are an estimated 60,000 preventable deaths per year. Hence, in the future it will be imperative to (1) identify patients at risk, (2) to prevent the development of postoperative complications with the use of adequate adjunctive therapeutic strategies, (3) to establish surveillance and monitoring systems for the early detection of postoperative complications and (4) to treat postoperative complications efficiently and in time when they arise.

Epidemiology of the high-risk population: perioperative risk and mortality after surgery.

PURPOSE OF REVIEW: This review will provide an overview of actual data concerning perioperative risk. Furthermore, strategies to prevent, detect and treat perioperative complications will be discussed. RECENT FINDINGS: Perioperative in-hospital mortality rate of 0.4-4% has not improved over the last years possibly resulting in one to several million deaths during or immediately after surgery each year worldwide. Perioperative complications and mortality are determined not only by the type of surgery but also by preexisting comorbidities of the patient. However, most potentially lethal complications have a slow onset like surgical site infections, pneumonia and sepsis. Therefore, a time window of opportunity might exist to detect and treat these complications as well as to improve outcome. In this context, failure to rescue (FTR) has been introduced as an indicator for the quality of perioperative care. There is growing evidence that FTR is a relevant phenomenon in perioperative medicine, possibly accounting for almost half of postoperative mortality. SUMMARY: It is imperative to reliably identify patients at risk for postoperative complications and to implement strategies into clinical practice allowing for prevention, early detection and effective treatment of complications. By bundling best practice concepts in all phases of perioperative care, patient outcome will be effectively improved.

[Anesthesia in children and adolescents with congenital heart defects]. / Anästhesie bei Kindern und Jugendlichen nach angeborenen Herzfehlern.

The incidence of congenital heart defects (CHD) has remained constant over many years; however, due to improved therapeutic options an increasing number of children and adolescents even with complex heart defects now reach adulthood. The increasing prevalence of adults with persisting or surgically corrected CHD as well as age-dependent non-cardiac comorbidities will increase the need for medical and non-cardiac surgical treatment in this population. Although elective medical care for these patients should be reserved for highly specialized centers, emergency treatment might become necessary in a non-specialized hospital setting as well. Due to the variety and complexity of CHD it is difficult to provide standardized guidelines for the anesthetic management. The treatment of patients with complex CHD requires a profound understanding of the underlying CHD and the current state of the hemodynamics by the anesthesiologist. Furthermore, typical comorbidities, such as chronic heart failure, altered coagulation and arrhythmia also have to be taken into account to ensure successful perioperative treatment. Especially in patients with shunt lesions or passive pulmonary blood flow the anesthetic management often substantially affects the hemodynamics and may be the starting point of severe decompensation. Awareness of anesthesia-induced changes of pulmonary and/or systemic vascular resistance as well as of preload alterations are the basis for successful anesthetic management. Finally, a multidisciplinary approach including cardiologists and radiologists in the planning is absolutely essential to achieve an optimal postoperative result for the patient.

[Rare complication after endoscopic discectomy]. / Seltene Komplikation der endoskopischen Nukleotomie.

Surgical treatment of the lumbar spine is a standard procedure in orthopedic and neurosurgery. After endoscopic discectomy an otherwise healthy patient developed massive dyspnea in combination with severe abdominal pain. Sonography revealed a large volume of free fluid in the abdominal cavity which proved to be surgical irrigation solution after computed tomography (CT) guided puncture. After insertion of a drainage channel fluid could be removed and the patient was transferred to a peripheral ward after a 24 h monitoring period. This review reports on the complications and anesthetic characteristics of percutaneous spinal interventions and presents differential diagnoses of postoperative dyspnea.

Pre-conditioning with synthetic CpG-oligonucleotides attenuates myocardial ischemia/reperfusion injury via IL-10 up-regulation.

The aim of the study was to investigate whether pre-conditioning with CpG-oligodeoxynucleotides (CpG-ODN) may change cardiac ischemia/reperfusion (I/R)-dependent inflammation and modulates infarct size and cardiac performance. WT and TLR9-deficient mice were pre-treated with 1668-, 1612- and H154-thioate or D-Gal as control. Priming with 1668-thioate significantly induced inflammatory mediators in the serum and a concomitant increase of immune cells in the blood and spleen of WT mice. Furthermore, it induced myocardial pattern recognition receptors and pro-inflammatory cytokines peaking 2 h after priming and a continuous increase of IL-10. 16 h after pre-conditioning, myocardial ischemia was induced for 1 h. Infarct size determined after 24 h of I/R was reduced by 75 % due to pre-conditioning with 1668-thioate but not in the other groups. During reperfusion, cytokine expression in 1668-thioate primed mice increased further with IL-10 exceeding the other mediators by far. These changes were observed neither in animals pre-treated with 1612- or H154-thioate nor in TLR9-deficient mice. The 1668-thioate-dependent increase of IL-10 was further supported by results of a micro-array analysis 3 h after begin of reperfusion. Block of IL-10 signaling increased I/R size and prevented influence of priming. In the group pre-treated with 1668-thioate, cardiac function was preserved 24 h, 14 days and 28 days after I/R, whereas animals without pre-conditioning exhibited impaired heart function 24 h and 14 days after I/R. The excessive 1668-thioate-dependent IL-10 up-regulation during pre-conditioning and after I/R seems to be the key factor for reducing infarct size and improving cardiac function. This is in agreement with the finding that IL-10 block prevents cardioprotection by pre-conditioning.

In vivo TLR9 inhibition attenuates CpG-induced myocardial dysfunction.

The involvement of toll-like receptor 9 (TLR9), a receptor for bacterial DNA, in septic cardiac depression has not been clarified in vivo. Thus, the aim of the study was to test possible TLR9 inhibitors (H154-thioate, IRS954-thioate, and chloroquine) for their ability to protect the cardiovascular system in a murine model of CpG oligodeoxynucleotide- (ODN-) dependent systemic inflammation. Sepsis was induced by i.p. application of the TLR9 agonist 1668-thioate in C57BL/6 wild type (WT) and TLR9-deficient (TLR9-D) mice. Thirty minutes after stimulation TLR9 antagonists were applied i.v. Survival was monitored up to 18 h after stimulation. Cardiac mRNA expression of inflammatory mediators was analyzed 2 h and 6 h after stimulation with 1668-thioate and hemodynamic parameters were monitored at the later time point. Stimulation with 1668-thioate induced a severe sepsis-like state with significant drop of body temperature and significantly increased mortality in WT animals. Additionally, there was a time-dependent increase of inflammatory mediators in the heart accompanied by development of septic heart failure. These effects were not observed in TLR9-D mice. Inhibition of TLR9 by the suppressive ODN H154-thioate significantly ameliorated cardiac inflammation, preserved cardiac function, and improved survival. This suppressive ODN was the most efficient inhibitor of the tested substances.

[Cardiopulmonary bypass in cardiac surgery]. / Kardiopulmonaler bypass in der herzchirurgie.

Cardiopulmonary bypass (CPB) is a standard procedure in cardiac surgery; however, apart from its therapeutic options a CPB might also initiate systemic and organ-specific complications, such as heart failure, renal and pulmonary dysfunction, impaired coagulation as well as neurological and cognitive dysfunction. The immunological response to the extracorporeal circulation generates systemic inflammation which often meets the definition of systemic inflammatory response syndrome (SIRS). The main inducers of SIRS are contact of blood with the artificial surfaces of the CPB, mechanical stress which affects the blood components and the extensive surgical trauma. Hence, a number of technical and surgical developments aim at reduction of the inflammatory response caused by the CPB. By reason of surgical demands, the majority of cardiothoracic procedures still depend on the use of CPB; however, there is an on-going development of new techniques trying to reduce the surgical trauma and the negative consequences of CPB. Here, minimized systems with biocompatible surfaces have been shown to be effective in attenuating the inflammatory response to CPB. Alternative procedures such as off-pump surgery may help to avoid CPB-associated complications but due to specific limitations will not replace conventional bypass surgery.

[Student evaluation of anesthesiological teaching: steering instrument of a continuous improvement process]. / Studentische Evaluation der anästhesiologischen Lehre : Steuerinstrument eines kontinuierlichen Verbesserungsprozesses.

BACKGROUND: The amendment to the higher education act ("Hochschulrahmengesetz") of 1998 postulates an evaluation of teaching for quality assurance. Hence, in the winter semester of 2004 the University Medical Center of Bonn introduced a semester questionnaire for students to evaluate the quality of teaching (EVALON). This evaluation is designed to be an objective benchmarking tool which is used for the distribution of university funds. It is also a steering instrument for direct improvement of teaching in clinical subjects. The aim of this study was to investigate, whether EVALON improved the quality of teaching between 2006 and 2010 and whether the department of anesthesiology improved its ranking in comparison with the other participating institutes. MATERIALS AND METHODS: Data from the EVALON questionnaire from the years 2006-2010 were analyzed for improvements in the quality of teaching in anesthesiology. This study focused on three essential contents of the EVALON questionnaire (structural content and organizational procedure of lectures and seminars, course presentation), which were used for the generation of a ranking list of all participating medical institutes and departments. On the basis of these results, 12.5% of the funding was assigned for educational purposes. RESULTS: There was an average return rate of the questionnaires of 74.5%. A significant increase in the overall assessment score of 43.4% could be observed from 5.3 in the summer semester of 2006 to 7.6 in the winter semester of 2009/10. The evaluation score for the department of anesthesiology concerning structural content of seminars and lectures increased by 79% from 4.8 in 2006 to 8.6 in 2010. The quality of organizational procedure was evaluated with a score of 4.9 in 2006 and improved by 74% to 8.5 in 2010. The course presentation skills of the teachers as evaluated by EVALON improved by 61% from a score of 5.2 in 2006 to 8.4 in 2010. In comparison with all other participating medical institutes the department of anesthesiology improved its ranking from position 36 in the winter semester 2006 to position 2 in the summer semester 2010. CONCLUSIONS: The reorganization of teaching anesthesiology, directly controlled by the results of EVALON improved the ranking of the department of anesthesiology. There was also a concomitant increase of the performance-oriented allocation of funds assigned to the department of anesthesiology based on the EVALON results.

Systemically administered ligands of Toll-like receptor 2, -4, and -9 induce distinct inflammatory responses in the murine lung.

OBJECTIVE: To determine whether systemically administered TLR ligands differentially modulate pulmonary inflammation. METHODS: Equipotent doses of LPS (20 mg/kg), CpG-ODN (1668-thioat 1 nmol/g), or LTA (15 mg/kg) were determined via TNF activity assay. C57BL/6 mice were challenged intraperitoneally. Pulmonary NFκB activation (2 h) and gene expression/activity of key inflammatory mediators (4 h) were monitored. RESULTS: All TLR ligands induced NFκB. LPS increased the expression of TLR2, 6, and the cytokines IL-1αß, TNF-α, IL-6, and IL-12p35/p40, CpG-ODN raised TLR6, TNF-α, and IL12p40. LTA had no effect. Additionally, LPS increased the chemokines MIP-1α/ß, MIP-2, TCA-3, eotaxin, and IP-10, while CpG-ODN and LTA did not. Myeloperoxidase activity was highest after LPS stimulation. MMP1, 3, 8, and 9 were upregulated by LPS, MMP2, 8 by CpG-ODN and MMP2 and 9 by LTA. TIMPs were induced only by LPS. MMP-2/-9 induction correlated with their zymographic activities. CONCLUSION: Pulmonary susceptibility to systemic inflammation was highest after LPS, intermediate after CpG-ODN, and lowest after LTA challenge.

Nitric oxide and pro-inflammatory cytokines correlate with pain intensity in chronic pain patients.

OBJECTIVE: Inflammatory cytokines as well as nitric oxide (NO) play a key role in the pathogenesis of persistent and exaggerated pain states. To document this, we investigated whether a range of cytokines and NO were detectable in the plasma of chronic pain patients and whether cytokine and NO levels correlated with pain severity. METHODS: Plasma samples of 94 chronic pain patients and 6 healthy volunteers were obtained. Average pain intensity during the last 24 h was assessed on a 11-point numeric rating scale and patients were distributed to three groups: light, moderate and severe pain. The concentrations of TNF-alpha, GM-CSF, interleukin (IL)-1beta, IL-6, IL-8, interferon (IFN)-gamma, IL-2, IL-4, IL-5, IL-10 and nitrate/nitrite were determined. RESULTS: Patients with light pain demonstrated significantly increased levels of IL-6 compared to controls. In the severe pain group IL-6 and nitrate/nitrite were significantly increased. Serum concentrations of IL-1beta, TNF-alpha, IL-2 and IL-4 were increased but as we adjusted the level of significance at p = 0.0045, most cytokine plasma levels failed to reach statistical significance. CONCLUSIONS: Pro-inflammatory cytokines (IL-1beta, IL-2, IL-6, IFN-gamma, TNF-alpha) in the plasma correlate with increasing pain intensity. Chronic pain patients show a significant increase in plasma levels of NO in comparison to healthy controls.