Resolving non‐symmetry in flows via subdomain shifts

In this study, non‐symmetric flow problems are modeled by selecting subdomains and shifting them in such a way that the symmetry is recovered. As a result, the domains are made of simple grid structures and re‐generation of mesh is avoided. Three test problems with various decomposition characteristics, namely, translation, rotation and deformation are selected, and they are analyzed in different flow regimes. To study the internal flow between eccentric cylinders, two cylindrical concentric subdomains are considered, one translated relative to the other. Hence, a simple polar‐coordinates mesh can be utilized instead of generating a mesh for the solution domain between the eccentric cylinders of the original problem. External flow around a curvature tube is studied shifting the subdomain around the object in rotation, relative to the outer domain thus avoiding a re‐generation of the mesh as the angle‐of‐attack changes. A third example involves deformation of an object exposed to natural convection, and the shifting of the domain facilitates the iteration process as the object deflects. Systems of nonlinear equations are solved within Newton‐Krylov framework using the matrix‐free approach. Geometrical and physical parameters are used to improve the solution process. Several results are provided to show the applicability of proposed method. First published online: 09 Jun 201

Hypertensive Encephalopathy and Renal Failure in a Young Man

No abstract available

Daha azı da mümkün: Düşük akımlı anestezide akım hızlarının güvenlik sonlanımları üzerine etkisi

Objective: Although various issues about low flow anaesthesia had been investigated previously, impact of different flow rates on perioperative follow-up and safety outcomes were not well-addressed. Here, we aimed to assess the influence of different flow rates of low flow fresh gas mixtures on hemodynamic state, gas exchange parameters and recovery time during general anaesthesia of urogenital system operations in a single tertiary centre. Materials and Methods: Sixty-two patients (American Society of Anaesthesiologists score I or II) to whom low flow anaesthesia with sevoflurane had been administered were subsequently gathered in three distinct -A, moderate flow (2 L/minimum), B, low flow (1 L/minimum), C, minimal flow (0.5 L/minimum) -groups. Hemodynamic data before and during anaesthesia, additionally, gas exchange and blood gas analysis parameters at 30th minute and before cessation of anaesthesia were recorded. Recovery period was observed by a second physician and times of interest were noted. Results: Demographic characteristics were similar among study groups. Most of the data regarding vital signs, gas exchange and blood gas analysis at the 30th minute and prior to cessation of anaesthesia were comparable. During operation, inspiratory sevoflurane levels were significantly higher in group A (1.7±0.6 vs 1.3±0.3 vs 1.3±0.3, p=0.043). There were no significant differences between the groups in terms of recovery data [time to spontaneous breathing (p=0.21), time to extubation (p=0.113), time to eye opening (p=0.5), time to verbal response (p=0.518) and time to reach a Modified Aldrete score of 9 or 10 (minimum, 13.7±6.8 vs 13.6±5.2 vs 14.8±4, p=0.717)]. Conclusion: Limiting the flow rate of gas mixture to 0.5 L/minutes in low flow anaesthesia maintenance may facilitate reduced utilization of volatile anaesthetics without a compromise in hemodynamic status and recovery process.Amaç: Düşük akımlı anesteziyle ilişkili birçok araştırma yapılmış olsa da, operasyon sırasında takip verileri ve güvenlik sonlanımları üzerine farklı akım hızlarının etkileri net olarak bilinmemektedir. Üçüncü basamak bir merkezde ürogenital sistem operasyonları sırasında uygulanan genel anestezi için düşük akımlı taze gaz karışımlarının farklı akım hızlarında kullanıldığı bu çalışmada, hemodinami, gaz değişim verileri ve derlenme zamanlarının gruplar arasında farklılık arz edip etmediği araştırılmıştır. Gereç ve Yöntemler: Sevofluran ile düşük akımlı anestezi uygulanan ardışık altmış iki hasta (Amerikan Anestezistler Derneği skoru I veya II) üç grupta toplandı: A, orta akım (2 L/dk), B, düşük akım (1 L/dk), C, minimal akım (0,5 L/dk). Operasyon öncesinde ve sırasında kaydedilen hemodinamik verilere ek olarak, 30. dakika ve anestezi sonlandırılmadan hemen önceki gaz değişim ve arter kan gazı değerleri incelendi. Derlenme ikinci bir hekim tarafından gözlendi ve gerekli süreler not edildi. Bulgular: Çalışma grupları arasında demografik özellikler benzerdi. Otuzuncu dakika ve anestezi sonlanımı öncesi vital bulgular, gaz değişim ve arter kan gazı analizi sonuçlarının çoğunluğu karşılaştırılabilir düzeydeydi. Operasyon sırasında, inspiratuvar sevofluran düzeyleri grup A’da anlamlı olarak daha yüksekti (%, 1,7±0,6 ve 1,3±0,3 ve 1,3±0,3, p=0,043). Derlenme zamanları açısından gruplar arasında fark tespit edilmedi [spontan soluma zamanı (p=0,21), ekstübasyon zamanı (p=0,113), göz açma zamanı (p=0,5), sözel yanıt zamanı (p=0,518) ve Modifiye Aldrete skoru 9 veya 10’a ulaşmaya kadar geçen süre (dk, 13,7±6,8 ve 13,6±5,2 ve 14,8±4, p=0,717)]. Sonuç: Düşük akımlı anestezi idamesinde gaz karışımının akım hızını 0,5 L/dk’ya kadar düşürmek, hemodinamik istikrar ve derlenme sürecine ilişkin herhangi bir taviz vermeden volatil anestetik ajanların tüketiminin azaltılmasına yardımcı olabilir

Effects of lithotomy and prone positions on hemodynamic parameters, respiratory mechanics, and arterial oxygenation in percutaneous nephrolithotomy performed under general anesthesia

Aim: The position of the body during surgery may affect the patient’s body functions, especially the hemodynamic parameters. We aimed to comparatively analyze the effects of lithotomy and prone position on respiratory mechanics, arterial oxygenation, and hemodynamic parameters in patients who underwent percutaneous nephrolithotomy (PNL). Materials and methods: The study included 40 patients aged 16-63 years who underwent kidney stone surgery. The patients had no history of diabetes or cardiopulmonary disease and had an American Society of Anesthesiology (ASA) score of I–II. The pH, partial arterial oxygen pressure, partial arterial carbon dioxide pressure, HCO3, arterial oxygen saturation, end-tidal carbon dioxide (EtCO2), alveolar oxygen partial pressure, dead space volume/tidal volume ratio, P(A-a)O2, peak inspiratory pressure (PIP), inspiratory plateau airway pressure (PPlt), systolic arterial pressure, diastolic arterial pressure, mean arterial pressure, and heart rate (HR) values were assessed simultaneously throughout the surgery and comparatively analyzed both for lithotomy and prone positions. Results: There was a significant difference between lithotomy and prone positions with regard to pH and HCO3 values, which are among the arterial blood gas parameters measured at 20 minutes (p<0.05 and p<0.001, respectively). There was a significant difference between lithotomy and prone positions with regard to EtCO2, PIP, PPlt, and HR measured at 20 minutes (p<0.05, p<0.001, p<0.001, and p<0.05, respectively). Conclusions: The prone position decreased dynamic and static compliance and increased the PIP and PPlt values in patients undergoing PNL. However, these changes do not have a negative effect on the hemodynamic parameters in low-risk patients

Prediction of Hemodynamic Reactivity during Sevoflurane Remifentanyl Anesthesia for Laparoscopic Cholecystectomy Using Analgesia Nociception Index

Aim: Pneumoperitoneum may cause serious side effects in high-risk patients during laparoscopic cholecystectomy. Perioperative analgesic sufficiency has been measured by the Analgesia Nociception index (ANI) in recent years. We examine the possibility of predicting hemodynamic reactivity by observing sudden changes in ANI during operation. Methods: In this retrospective study, recorded hemodynamic parameters (including heart rate, systolic/ diastolic blood pressure values) and ANI values, before and after intubation, nasogastric tube application, intraperitoneal gas insufflation, and surgical incision in 31 patients who were applied laparoscopic cholecystectomy were compared by paired t-test. Additionally, an increment or decrement of 20% in ANI and 15% in hemodynamic parameters with respect to basal observation values were called “sudden changes”. Correlation of these parameters with sudden changes in ANI values was examined either. Results: There was a statistically significant difference in parameters after premedication and intubation. After induction, a statistically significant decrement was detected only in heart rate and systolic/diastolic blood pressure values. There was no significant change after nasogastric tube insertion. During pneumoperitoneum and surgical incision, there was no change in heart rate and systolic/diastolic blood pressure values, but a statistically significant decrement was observed in ANI. No correlation was detected between sudden changes in ANI values and hemodynamic parameters. Conclusion: We assume that use of ANI in analgesia evaluation under general anesthesia at perioperative period is suitable, however, it is not reliable in predicting hemodynamic interaction

DATE OF APPROVAL: 26.01.2006

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Assessment of Mean Platelet Volume in Patients with AA Amyloidosis and AA Amyloidosis Secondary to Familial Mediterranean Fever: A Retrospective Chart - Review Study

WOS: 000469780200001PubMed ID: 31123243Background: Amyloidosis is a protein-misfolding disease characterized by the deposition of aggregated proteins in the form of abnormal fibrils that disrupt tissue structure, ultimately causing disease. Amyloidosis is very frequent in untreated familial Mediterranean fever (FMF) patients and it is the most important feature that determines the prognosis of FMF disease. The mean platelet volume (MPV) in FMF has been previously studied. However, whether MPV level in FMF patients is lower or higher compared to healthy controls remains a topic of ongoing debate. In this study, we aimed to investigate MPV values and to assess the correlation between MPV and proteinuria in patients with AA amyloidosis and AA amyloidosis secondary to familial Mediterranean fever (AA-FMF) through a retrospective chart-review. Material/Methods: This study was carried out on 27 patients with AA amyloidosis, 36 patients with AA amyloidosis secondary to FMF (a total of 63 patients with AA), and 29 healthy controls. There was no statistically significant difference between the AA patients and the control group (p=0.06) or between the AA-FMF group and the control group in terms of MPV values (p=0.12). Results: We found a statistically significant negative correlation between MPV and thrombocyte count in all groups (p<0.05 for all groups), but there was no correlation between MPV and proteinuria levels in AA patients (p=0.091). Conclusions: While similar results also exist, these findings are contrary to the majority of previous studies. Therefore, further controlled clinical prospective trials are necessary to address this inconsistency

AA Amiloidozlu Hastalarda Serum FGF-23 Düzeyi Subklinik Aterosklerozun Göstergesi midir?

Objective: Amyloid A (AA) amyloidosis is the most prevalent form of systemic amyloidosis, and is a serious condition characterized by protein-misfolding. Cardiovascular involvement is known to be a significant manifestation of the disease and common carotid artery intima-media thickness (CIMT) assessment is one of the well-recognized tools for identification of subclinical atherosclerosis. It was reported that FGF-23 may be a significant factor associated with atherosclerosis development in patients with AA amyloidosis, as well as being an independent risk factor for increased CIMT. In this study, we aimed to investigate whether elevated FGF-23 levels might be associated with CIMT levels in AA amyloidosis patients. Method: We studied 63 patients with AA amyloidosis and 29 aged-matched healthy controls. All subjects’ demographic data were recorded and the following parameters were measured: erythrocyte sedimentation rate, C-reactive protein, creatinine, urea, albumin, calcium, phosphate, parathyroid hormone, FGF-23, eGFR, CIMT, blood pressure and BMI. Results: CIMT levels were significantly higher in AA amyloidosis patients compared to the control group (p<0.001). However, serum FGF-23 levels were similar (p=0.110). CIMT was correlated with patient age (r=0.471, p<0.001), but serum FGF-23 was not associated with CIMT in patients with amyloidosis (r=0.031, p=0.807). Conclusion: Although our results suggest a lack of association between FGF-23 levels and CIMT in patients with AA amyloidosis.Amaç: Amiloidoz proteinlerin anormal katlantı oluşturması ile karekterize hayatı tehdit eden bir hastalıktır, Amyloid-associated (AA) amiloidoz sistemik amiloidozun en yaygın formudur. Kardiyovasküler tutulum amiloidozun en önemli klinik tezahürüdür ve karotis intima media kalınlığının ölçümü (KIMK) subklinik aterosklerozu tespit etmek için iyi tanımlanmış yöntemlerden birisidir. FGF-23 AA amiloidozda KIMK’dan bağımsız olarak subklinik ateroskleroz ile ilişkili olabileceği bildirilmiştir. Bu çalışmada amacımız, AA amiloidozlu hastalarda KIMK ile yükselmiş serum FGF-23 ile ilişkisinin olup olmadığına bakmaktı. Yöntem: Çalışmaya 63 AA amiloidozlu hasta ve 29 sağlıklı kontrol dahil ettik. Tüm olguların demografik verileri, eritrosit sedimantasyon hızı, Crp, kreatinin, üre, albumin, kalsiyum, fosfat, parathormon, FGF-23, eGFR, KIMK, kan basıncı ve vücut kitle indeksleri kayıt edildi. Bulgular: Karotis intima media kalınlığı AA amiloidozlu hastalarda kontrol grubuna göre anlamlı derecede fazlaydı (p<0.001). Bununla birlikte serum FGF-23 seviyesi iki grup arasında farklı değildi (p =0.110). KIMK yaş ile köreleydi (r=0.471, p<0.001), fakat serum FGF-23 seviyesi amiloidozlu hastalarda KIMK ile körele değildi (r=0.031, p=0.807). Sonuç: Bizim çalışmamızda, AA amiloidozlu hastalarda KIMK ile Serum FGF-23 seviyesi arasında bir korelasyon tespit edilememiştir

Demographic and Clinical Characteristics of Patients with Autosomal Dominant Polycystic Kidney Disease: A Multicenter Experience

Aim: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease. It accounts for 5-10% of patients with end-stage renal disease (ESRD). The aim of this multicenter study was to investigate the demographic and clinical characteristics of patients with ADPKD. Methods: 1,139 patients with ADPKD who were followed up at 12 different centers were recruited for this study. The investigated demographic and clinical characteristics were gender, age, smoking history, educational status, the existence of hypertension, hematuria, urinary tract infection, urinary tract stones and renal replacement therapy. Patients were considered as hypertensive if they were taking antihypertensive medications or if they had blood pressure (BP) of 140/90 mm Hg or greater. If the patients were currently on antihypertensive drugs, the classes of these agents were noted. Results: 548 male and 591 female patients were included and the mean age at initial diagnosis was 37.1 +/- 16.3 years. 20.3% were current smokers whereas 15% were ex-smokers. The mean systolic and diastolic BPs were 136.1 +/- 29.8 and 84.9 +/- 17.8 mm Hg, respectively. 63.7% used antihypertensive drugs and 73.1% of those used renin-angiotensin system blockers. 11.8% had ESRD, of which 75.8% were treated with hemodialysis. Conclusion: This study showed that hypertension is the most common (72.6%) clinical finding in ADPKD patients in Turkey and renin-angiotensin system blockers are widely used. Copyright (C) 2010 S. Karger AG, Base