[Perioperative visual loss : Rare, unknown, relevant?] / Perioperativer Visusverlust : Selten, unbekannt, relevant?

Perioperative visual loss (POVL) is a rare but severe complication following non-ophthalmological surgery under general anesthesia. A POVL can be caused by lesions in any part of the optical system. The predominant causes include corneal injuries and particularly ischemic damage. The symptoms of POVL substantially vary ranging from reduced vision to complete blindness. The risks involve factors related to the surgery as well as patient-specific factors. In general, the prognosis in cases of mechanical damage is better than for ischemic lesions. The treatment measures depend on the underlying pathomechanism and due to the limited evidence only a few treatment options are available. Therefore, preventive measures and meticulous documentation play a crucial role.

[The Status of Spiroergometry in Preoperative Risk Assessment]. / Spiroergometrie ­ Stellenwert in der präoperativen Risikobeurteilung.

Physical performance is considered as a prognostic factor for perioperative mortality and morbidity. Thus, in recent years, spiroergometry has gained increasing significance in preoperative assessment. Beside the measurement of functional capacity, spiroergometric results may yield indications for cardiocirculatory or pulmonary disorders. A significant increased risk profile is reflected in the values VO2max < 15 ml/kg/min, VO2 at the first ventilatory threshold (VT1) < 11 ml/kg/min, and VE/VCO2 at VT1 > 34. Prior to the examination, contraindications should be taken into account and standardized conduction must be adhered to. Many studies substantiate the positive effect of prehabilitation on morbidity, quality of life, and length of hospitalization, in particular in abdominal, thoracic and hepatobiliary surgery. Using the data acquired in the performance diagnostic, an optimized individual training plan can be drawn up. Besides, the risk evaluation contributes to planning surgical and anaesthetic procedures. Regular training and interdisciplinary teamwork are of utmost importance for the correct interpretation and application of the partly rather complex results.

The effect of wearing an FFP3 mask (3MTM AuraTM) with an exhalation valve on gas exchange in medical staff.

OBJECTIVES: The physiological impact of wearing personal protective equipment (PPE), in particular filtering-face-piece 3 (FFP3) masks, has increasingly been gaining importance since the outbreak of coronavirus disease 2019 (COVID-19). So far, gas exchange has been examined using transcutaneously measured partial pressure of carbon dioxide (PaCO2), ergo-spirometry and impedance cardiography. MATERIAL AND METHODS: In this structured investigation, arterial blood gas analysis in a 30-year-old female resident was carried out during a 13-hour day shift on the COVID-19 Intensive Care Unit of the University Hospital of Innsbruck, Austria. An FFP3 mask (3MTM AuraTM) with an exhalation valve was continuously worn, except for 1 break of 20 min. Arterial blood samples were obtained before putting on the PPE, and after 5 h, 9 h and 13 h of working in the contaminated area. RESULTS: During the multi-hour wearing time, an increase in PaCO2 (the baseline value: 29.3 mm Hg, the max. value: 38.9 mm Hg) and a continuous decrease in partial pressure of oxygen (PaO2, the baseline value: 102 mm Hg, the min. value: 80.8 mm Hg) was detectable. CONCLUSIONS: All measured values were within the normal range, but a trend towards an insufficient gas exchange could be suspected. Int J Occup Med Environ Health. 2021;34(6):817-9.

Guided vs. non-guided insertion of Ambu AuraGain™ in edentulous patients.

BACKGROUND: Supraglottic airway devices perform more poorly and have lower oropharyngeal leak pressure in edentulous patients than in patients with teeth. The Ambu Aura Gain is a newer second generation supraglottic airway device. OBJECTIVE: This randomized clinical trial assessed the oropharyngeal leak pressure in edentulous patients using the Ambu Aura Gain with a gastric tube for insertion guidance and without insertion guidance. MATERIAL AND METHODS: Patients with ASA (American Society of Anesthesiology) physical status I-III were recruited. Primary outcome was oropharyngeal leak pressure after insertion. Secondary outcome parameters were oropharyngeal leak pressure 15 min and 30 min after insertion, insertion time, insertion attempts and glottis view through flexible fiberscope. RESULTS: In this study 72 patients aged between 51 and 90 years (mean 73 years) were randomly allocated to the "with guidance" (n = 36) or the "without guidance" group (n = 36). Mean (SD) oropharyngeal leak pressure in "with guidance" and "without guidance" group was 24 cm H2O and 24 cm H2O (ns), respectively. A difference was found in mean insertion time with guidance versus without guidance group 52 s (45 s) vs. 26 s (15 s) (p < 0.001). No difference was found in any of the other secondary outcome parameters. CONCLUSION: A guided insertion technique does not improve oropharyngeal leak pressure of the Ambu AuraGain™ in edentulous patients. As the only difference is an increase in insertion time this technique is of no benefit for this population.

The 'rejuvenating factor' TIMP-2 is detectable in human blood components for transfusion.

BACKGROUND AND OBJECTIVES: Tissue inhibitor of metalloproteinases 2 (TIMP-2) is a protein suspected to be crucial in numerous physiological and pathological processes such as morphogenesis, tissue remodelling and metastasis suppression. In animal models, the administration of TIMP-2 to aged mice improved their cognitive functions. Therefore, one can hypothesize that differences in TIMP-2 levels between blood donors and recipients might influence cognitive functions also in humans. However, the stability of TIMP-2 during processing and storage of blood components for transfusion has not been intensively investigated so far. This study determined TIMP-2 concentrations in fresh-frozen plasma (FFP), erythrocyte concentrate (EC) and pathogen-inactivated platelet concentrate (PI-PC) depending on the donor's demographic factors age and gender. MATERIALS AND METHODS: Tissue inhibitor of metalloproteinases 2 was measured in FFP (n = 30), EC (n = 12) and PI-PC (n = 12) using a Q-Plex single-plex immunoassay for chemiluminescence-based detection. Absolute quantification of TIMP-2 was performed with Q-view software. Fresh umbilical cord plasma was used as a positive control. RESULTS: Tissue inhibitor of metalloproteinases 2 was detected in FFP (30/30 samples), EC (11/12 samples) and PI-PC (12/12 samples). The median TIMP-2 concentration in EC (17·2 ng/ml; range: 0-26·5 ng/ml) was significantly lower compared with FFP (63·4 ng/ml; range: 44·4-87·3 ng/ml) or PI-PC (69·9 ng/ml; range: 39·9-83·6 ng/ml). Across all blood components, TIMP-2 levels are comparable in male and female donors and independent of age. CONCLUSION: Tissue inhibitor of metalloproteinases 2 is detectable and stable in FFP, PI-PC and, in low concentration, EC. It can be hypothesized that TIMP-2 will be transmitted to recipients during transfusion.

Cerebrospinal beta-amyloid peptides(1-40) and (1-42) in severe preeclampsia and HELLP syndrome - a pilot study.

During pregnancy, substantial alterations in cerebral plasticity, vascular remodeling and neuronal growth occur in the maternal brain. We investigated whether concentrations of selected neurodiagnostic biomarkers in the cerebrospinal fluid of women with preeclampsia/HELLP syndrome differ from those in healthy controls using enzyme-linked immunosorbent assay technique. We found that tau protein concentrations (p = 0.016) and phospho-tau/tau ratio (p < 0.001) in cerebrospinal fluid were significantly lower in 39 preeclamptic women compared to 44 healthy controls during third trimester of pregnancy. Beta-amyloid(1-40)/(1-42) ratio was significantly higher in HELLP syndrome than in severe preeclampsia (8.49 + 2.73 vs. 4.71 + 1.65; p = 0.007). We conclude that beta-amyloid(1-40)/(1-42) ratio in cerebrospinal fluid can discriminate severe preeclampsia and HELLP syndrome. High beta-amyloid peptide and low tau protein concentrations are associated with impaired development of the materno-feto-placental unit and correlate with placental dysfunction.