Perioperative Fluid Management.

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the elderly are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the elderly. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

Selected Transesophageal Echocardiographic Parameters of Left Ventricular Diastolic Function Predict Length of Stay Following Coronary Artery Bypass Graft-A Prospective Observational Study.

(1) Importance: Abnormal left ventricular (LV) diastolic function, with or without a diagnosis of heart failure, is a common finding that can be easily diagnosed by intra-operative transesophageal echocardiography (TEE). The association of diastolic function with duration of hospital stay after coronary artery bypass (CAB) is unknown. (2) Objective: To determine if selected TEE parameters of diastolic dysfunction are associated with length of hospital stay after coronary artery bypass surgery (CAB). (3) Design: Prospective observational study. (4) Setting: A single tertiary academic medical center. (5) Participants: Patients with normal systolic function undergoing isolated CAB from September 2017 through June 2018. (6) Exposures: LV function during diastole, as assessed by intra-operative TEE prior to coronary revascularization. (7) Main Outcomes and Measures: The primary outcome was duration of postoperative hospital stay. Secondary intermediate outcomes included common postoperative cardiac, respiratory, and renal complications. (8) Results: The study included 176 participants (mean age 65.2 ± 9.2 years, 73% male); 105 (60.2%) had LV diastolic dysfunction based on selected TEE parameters. Median time to hospital discharge was significantly longer for subjects with selected parameters of diastolic dysfunction (9.1/IQR 6.6−13.5 days) than those with normal LV diastolic function (6.5/IAR 5.3−9.7 days) (p < 0.001). The probability of hospital discharge was 34% lower (HR 0.66/95% CI 0.47−0.93) for subjects with diastolic dysfunction based on selected TEE parameters, independent of potential confounders, including a baseline diagnosis of heart failure. There was a dose−response relation between severity of diastolic dysfunction and probability of discharge. LV diastolic dysfunction based on those selected TEE parameters was also associated with postoperative cardio-respiratory complications; however, these complications did not fully account for the relation between LV diastolic dysfunction and prolonged length of hospital stay. (9) Conclusions and Relevance: In patients with normal systolic function undergoing CAB, diastolic dysfunction based on selected TEE parameters is associated with prolonged duration of postoperative hospital stay. This association cannot be explained by baseline comorbidities or common post-operative complications. The diagnosis of diastolic dysfunction can be made by TEE.

Anesthetic Management During Lung Transplantation - What's New in 2021?

As outcomes of lung transplantation (LTx) are improving transplant centers are pushing boundaries. There has been a steady increase in the medical complexity of lung transplant candidates. Many transplant centers are listing older patients with comorbidities, and there has been a steady rise in the number of candidates supported with extracorporeal membrane oxygenation (ECMO) as a bridge to transplantation. There has been a growing appreciation of the importance intraoperative management of potentially modifiable risk factors has on postoperative outcomes. Evidence suggests that LTx even in high-risk patients requiring perioperative ECMO can offer excellent results. This article outlines the current state-of-the-art intraoperative management of LTx.

Hemodilution in high-risk cardiac surgery: Laboratory values, physiological parameters, and outcomes.

BACKGROUND: Acute normovolemic hemodilution (ANH) is a blood conservation strategy in cardiac surgery, predominantly used in coronary artery bypass graft (CABG) and/or valve procedures. Although higher complexity cardiac procedures may benefit from ANH, concerns for hemodynamic instability, and organ injury during hemodilution hinder its wider acceptance. Laboratory and physiological parameters during hemodilution in complex cardiac surgeries have not been described. STUDY DESIGN AND METHODS: This observational cohort (2019-2021) study included 169 patients who underwent thoracic aortic repair, multiple valve procedure, concomitant CABG with the aforementioned procedure, and/or redo sternotomies. Patients who received allogeneic blood were excluded. Statistical comparisons were performed between ANH (N = 66) and non-ANH controls (N = 103). ANH consisted of removal of blood at the beginning of surgery and its return after cardiopulmonary bypass. RESULTS: Intraoperatively, the ANH group received more albumin (p = .04) and vasopressor medications (p = .01), while urine output was no different between ANH and controls. Bilateral cerebral oximetry (rSO2 ) values were similar before and after hemodilution. During bypass, rSO2 were discretely lower in the ANH versus control group (right rSO2 p = .03, left rSO2 p = .05). No differences in lactic acid values were detected across the procedural continuum. Postoperatively, no differences in extubation times, intensive care unit length of stay, kidney injury, stroke, or infection were demonstrated. DISCUSSION: This study suggests hemodilution to be a safe and comparable blood conservation technique, even without accounting for potential benefits of reduced allogenic blood administration. The study may contribute to better understanding and wider acceptance of ANH protocols in high-risk cardiac surgeries.

Effects of acute normovolemic hemodilution on post-cardiopulmonary bypass coagulation tests and allogeneic blood transfusion in thoracic aortic repair surgery: An observational cohort study.

BACKGROUND AND AIM: Perioperative blood transfusion is associated with increased morbidity and mortality. Acute normovolemic hemodilution (ANH) is a blood conservation strategy associated with variable success, and rarely studied in more complex cardiac procedures. The study aim was to evaluate whether ANH improves coagulopathy and reduces blood transfusions in thoracic aortic surgeries. METHODS: Single-center observational cohort study comparing ANH and standard institutional practice in patients who underwent thoracic aortic repair with cardiopulmonary bypass (CPB) from 2019 to 2021. RESULTS: A total of 89 patients underwent ANH and 116 standard practice. There were no significant differences between the groups in terms of demographic or major perioperative characteristics. In the ANH group coagulation tests before and after transfusion of autologous blood showed decreased INR and increased platelets, fibrinogen, all with p < 0.0005. Coagulation results in the ANH and control groups were not statistically different. The average number of transfused allogeneic products per patient was lower in the ANH versus control group: FFP 1.1 ± 1.6 versus 1.9 ± 2.3 (p = 0.003), platelets 0.6 ± 0.8 versus 1.2 ± 1.3 (p = 0.0008), and cryoprecipitate 0.3 ± 0.7 versus 0.7 ± 1.1 (p = 0.008). Reduction in red blood cell transfusion was not statistically significant. The percentage of patients who received any transfusion was 53.9% in ANH and 59.5% in the control group (p = 0.42). There was no significant difference in major adverse outcomes. CONCLUSIONS: ANH is a safe blood conservation strategy for surgical repairs of the thoracic aorta. Laboratory data suggests ANH can improve some coagulation values after separation from CPB, and significantly reduce the number of transfused FFP, platelets and cryoprecipitate.

MicroRNAs contribute to the maintenance of cell-type-specific physiological characteristics: miR-192 targets Na+/K+-ATPase ß1.

MicroRNAs (miRNAs) play important roles in biological development and disease. Much less is known about their role in normal adult physiology. The proximal convoluted tubule (PCT) and the medullary thick ascending limb (mTAL) in the kidney consist of epithelial cells with different transport activities. We identified 55 possible miRNA-target pairs of which the miRNAs and their predicted target proteins, many of which are involved in epithelial transport, were inversely enriched in PCT and mTAL. Some miRNAs appeared to have synergistic effects on shared targets. miR-192 and its predicted target the ß-1 subunit of Na(+)/K(+)-ATPase (Atp1b1), an enzyme providing the driving force for tubular transport, were inversely enriched in kidney regions. In mice, knockdown of miR-192 led to up-regulation of Atp1b1 protein. When mice were fed with a high-salt diet, knockdown of miR-192 blunted the adaptational increase of urine output. Interestingly, miR-192 appeared to target Atp1b1 through the 5'-, rather than 3'-untranslated region. The study suggests a novel physiological mechanism in which miR-192 suppresses Na(+)/K(+)-ATPase and contributes to renal handling of fluid balance. It supports an important role of miRNAs in determining cellular characteristics that may appear subtle yet are physiologically critical.

MicroRNA-target pairs in human renal epithelial cells treated with transforming growth factor beta 1: a novel role of miR-382.

We reported previously an approach for identifying microRNA (miRNA)-target pairs by combining miRNA and proteomic analyses. The approach was applied in the present study to examine human renal epithelial cells treated with transforming growth factor ß1 (TGFß1), a model of epithelial-mesenchymal transition important for the development of renal interstitial fibrosis. Treatment of human renal epithelial cells with TGFß1 resulted in upregulation of 16 miRNAs and 18 proteins and downregulation of 17 miRNAs and 16 proteins. Of the miRNAs and proteins that exhibited reciprocal changes in expression, 77 pairs met the sequence criteria for miRNA-target interactions. Knockdown of miR-382, which was up-regulated by TGFß1, attenuated TGFß1-induced loss of the epithelial marker E-cadherin. miR-382 was confirmed by 3'-untranslated region reporter assay to target five genes that were downregulated at the protein level by TGFß1, including superoxide dismutase 2 (SOD2). Knockdown of miR-382 attenuated TGFß1-induced downregulation of SOD2. Overexpression of SOD2 ameliorated TGFß1-induced loss of the epithelial marker. The study provided experimental evidence in the form of reciprocal expression at the protein level for a large number of predicted miRNA-target pairs and discovered a novel role of miR-382 and SOD2 in the loss of epithelial characteristics induced by TGFß1.

Morphometric analysis of renal arteries in patients with renal cell carcinoma.

The aim of this study was to analyze morphometric parameters of renal arteries (longest diameter and tunica media thickness) in patients with renal cell carcinoma (RCC), to look into their relationship to tumor necrosis and to compare them with morphometric parameters recorded in a control group. We analyzed archival cases of RCC diagnosed in 2003 that also contained routinely sampled specimens of distal segments of renal artery. The control group consisted of specimens from both renal arteries obtained from 16 patients at routine autopsy during 2004-2005. Autopsy, as well as further histological analysis, did not disclose any malignant disease in the control group. Morphometric analysis of diameter and thickness of the renal artery tunica media was performed using Issa 3.1 software (Vamstek 2002, Zagreb, Croatia). The comparison of tunica media thickness showed that renal arteries from RCC cases were significantly thicker compared to distal parts of renal arteries in the control group (p=0.0002). Although renal artery samples from cases with necrotic tumor areas were thicker than those without tumor necrosis, the difference was not statistically significant. It is concluded that significantly thicker tunica media characterizes renal arteries in the group of patients with RCC when compared with the control group.

The correlation between the tumor necrosis and renal artery changes in renal cell carcinoma.

Necrosis, cysts, hemorrhage, and calcification represent common findings in renal cell carcinoma. Different lesions, including arteriosclerosis or fibromuscular dysplasia, or both, may involve the main renal artery. This study analyzed the relationship between the presence and extent of necrosis in renal cell carcinoma with renal artery changes in a consecutive series of 112 patients (71 men, 41 women) with mean renal cell carcinoma of 7.7 cm (range, 2 to 20 cm). Necrosis was seen macroscopically and confirmed microscopically in 88 cases (78.6%), with 64 tumors having less than 50% and 24 more than 50% necrosis. Fibromuscular dysplasia was found in 41 patients (36.6%; 17 men, 24 women) and atherosclerotic changes in 21 patients (18.8%; 18 men, 3 women). The results suggest that necrosis of renal cell carcinoma was significantly more common in women with associated fibromuscular dysplasia (especially type I) and men with atherosclerotic changes of renal artery.