Intraoperative Use of Albumin in Major Noncardiac Surgery: Incidence, Variability, and Association With Outcomes

BACKGROUND

The impact of albumin use during major surgery is unknown, and a dearth of evidence governing its use in major noncardiac surgery has long precluded its standardization in clinical guidelines.

OBJECTIVE

In this study, we investigate institutional variation in albumin use among medical centers in the United States during major noncardiac surgery and explore the association of intraoperative albumin administration with important postoperative outcomes.

METHODS

The study is an observational retrospective cohort analysis performed among 54 U.S. hospitals in the Multicenter Perioperative Outcomes Group and includes adult patients who underwent major noncardiac surgery under general anesthesia between January 2014 and June 2020. The primary endpoint was the incidence of albumin administration. Secondary endpoints are acute kidney injury (AKI), net-positive fluid balance, pulmonary complications, and 30-day mortality. Albumin-exposed and albumin-unexposed cases were compared within a propensity score-matched cohort to evaluate associations of albumin use with outcomes.

RESULTS

Among 614,215 major surgeries, predominantly iso-oncotic albumin was administered in 15.3% of cases and featured significant inter-institutional variability in use patterns. Cases receiving intraoperative albumin involved patients of higher American Society of Anesthesiologists physical status and featured larger infused crystalloid volumes, greater blood loss, and vasopressor use. Overall, albumin was most often administered at high-volume surgery centers with academic affiliation, and within a propensity score-matched cohort (n=153,218), the use of albumin was associated with AKI (aOR 1.24, 95% CI 1.20-1.28, P <0.001), severe AKI (aOR 1.45, 95% CI 1.34-1.56, P <0.001), net-positive fluid balance (aOR 1.18, 95% CI 1.16-1.20, P <0.001), pulmonary complications (aOR 1.56, 95% CI 1.30-1.86, P <0.001), and 30-day all-cause mortality (aOR 1.37, 95% CI 1.26-1.49, P <0.001).

CONCLUSIONS

Intravenous albumin is commonly administered among noncardiac surgeries with significant inter-institutional variability in use in the United States. Albumin administration was associated with an increased risk of postoperative complications.

Human red blood cell behaviour in hydroxyethyl starch: probed by single cell spectroscopy

Hydroxyethyl starch (HES) is a commonly used intravenous fluid in hospital settings. The merits and demerits of its application is still a debatable topic. Investigating the interaction of external agents like intravenous fluids with blood cells is of great significance in clinical environments. Micro-Raman spectroscopy combined with an optical tweezers technique has been utilized for conducting systematic investigations of single live red blood cells (RBCs) under the influence of external stress agents. The present work deals with a detailed biophysical study on the response of human live red blood cells in hydroxyethyl starch using optical techniques. Morphological changes in red blood cells were monitored using quantitate phase imaging techniques. Micro-Raman studies suggest that there is a significant reduction in the oxy-haemoglobin level in red blood cells suspended in HES. The spectra recorded by using different probe laser powers has shown that the cells are more vulnerable in HES under the influence of externally induced stress than in blood plasma. In addition, the spectral results support the possibility of heme aggregation and membrane damage for red blood cells in HES under externally induced stress. Principle component analysis performed on the Raman spectra were able to effectively discriminate between red blood cells in HES and in blood plasma. The use of Raman tweezers can be highly beneficial in elucidating biochemical alterations happening in live, human red blood cell.

Hydroxyethyl starch (HES) is a commonly used intravenous fluid in hospital settings.

Implementation of a classification strategy of Raman data collected in different clinical conditions: application to the diagnosis of chronic lymphocytic leukemia

The literature is rich in proof of concept studies demonstrating the potential of Raman spectroscopy for disease diagnosis. However, few studies are conducted in a clinical context to demonstrate its applicability in current clinical practice and workflow. Indeed, this translational research remains far from the patient's bedside for several reasons. First, samples are often cultured cell lines. Second, they are prepared on non-standard substrates for clinical routine. Third, a unique supervised classification model is usually constructed using inadequate cross-validation strategy. Finally, the implemented models maximize classification accuracy without taking into account the clinician's needs. In this paper, we address these issues through a diagnosis problem in real clinical conditions, i.e., the diagnosis of chronic lymphocytic leukemia from fresh unstained blood smears spread on glass slides. From Raman data acquired in different experimental conditions, a repeated double cross-validation strategy was combined with different cross-validation approaches, a consensus label strategy and adaptive thresholds able to adapt to the clinician's needs. Combined with validation at the patient level, classification results were improved compared to traditional strategies.

Genus- and species-level identification of dermatophyte fungi by surface-enhanced Raman spectroscopy

This paper demonstrates that surface-enhanced Raman spectroscopy (SERS) coupled with principal component analysis (PCA) can serve as a fast and reliable technique for detection and identification of dermatophyte fungi at both genus and species level. Dermatophyte infections are the most common mycotic diseases worldwide, affecting a quarter of the human population. Currently, there is no optimal method for detection and identification of fungal diseases, as each has certain limitations. Here, for the first time, we have achieved with a high accuracy, differentiation of dermatophytes representing three major genera, i.e. Trichophyton, Microsporum, and Epidermophyton. Two first principal components (PC), namely PC-1 and PC-2, gave together 97% of total variance. Additionally, species-level identification within the Trichophyton genus has been performed. PC-1 and PC-2, which are the most diagnostically significant, explain 98% of the variance in the data obtained from spectra of: Trichophyton rubrum, Trichophyton menatgrophytes, Trichophyton interdigitale and Trichophyton tonsurans. This study offers a new diagnostic approach for the identification of dermatophytes. Being fast, reliable and cost-effective, it has the potential to be incorporated in the clinical practice to improve diagnostics of medically important fungi.

Label-free molecular imaging of the kidney

In this review, we will highlight technologies that enable scientists to study the molecular characteristics of tissues and/or cells without the need for antibodies or other labeling techniques. Specifically, we will focus on matrix-assisted laser desorption/ionization imaging mass spectrometry, infrared spectroscopy, and Raman spectroscopy.

Postoperative Acute Kidney Injury and Blood Product Transfusion After Synthetic Colloid Use During Cardiac Surgery

OBJECTIVES

This study assessed the effect of 2 types of hydroxyethyl starches (HES) on renal integrity and blood transfusion in cardiac surgery patients.

DESIGN

Retrospective investigation.

SETTING

Patients from a single tertiary medical center.

PARTICIPANTS

Inclusion criteria included coronary artery bypass graft (CABG) and/or valve surgery that included cardiopulmonary bypass with aortic cross-clamping.

INTERVENTIONS

Intraoperative HES and blood product administration.

MEASUREMENTS AND MAIN RESULTS

The study comprised 1,265 patients who met inclusion criteria. Of these patients, 70% received HES, and of these, 47% received<1,000 mL and 53% received≥1,000 mL. There was no difference in the development of acute kidney injury between the 2 groups. A parsimonious propensity model for colloids showed that combined CABG and valve surgery were less likely to be associated with HES administration than was CABG alone (OR 0.68, confidence interval [CI] 0.46-0.97; p = 0.04). Intra-aortic balloon pump use was less likely to be associated with HES administration (OR 0.57, CI 0.38-0.86; p = 0.007). Patients with chronic kidney disease, stages 3 to 5, were less likely to receive HES, with an OR of 0.56 (CI 0.38-0.84; p = 0.004); 0.51 (CI 0.20-1.33; p = 0.170); and 0.23 (CI 0.12-0.44; p<0.0001), respectively, for each stage. No difference was noted in red blood cell transfusion. However, fresh frozen plasma, cryoprecipitate, and platelet transfusions were significantly higher with larger volumes of HES, with an OR of 2.03 (CI 1.64-2.52; p<0.001); 1.60 (CI 1.30-1.97; p<0.000); and 1.62 (CI 1.21-2.15; p = 0.006), respectively. No differences in surgical mortality were found between the colloid and noncolloid groups.

CONCLUSIONS

This study showed no association of postoperative acute kidney injury and red blood cell transfusion between the colloid and noncolloid groups. Although the complication rate was higher with HES administration, there was no difference in surgery mortality between the 2 groups.

Raman-based detection of hydroxyethyl starch in kidney allograft biopsies as a potential marker of allograft quality in kidney transplant recipients

In brain-dead donor resuscitation, hydroxyethyl starch (HES) use has been associated with presence of osmotic-nephrosis-like lesions in kidney transplant recipients. Our aim was to determine whether the presence of HES in protocol renal graft biopsies at three months (M3) after transplantation is associated with renal graft quality. According to the HES administered to the donor during the procurement procedure, two groups of patients were defined according graft exposition to HES: HES group, (N = 20) and control group (N = 6). Detection and relative quantification of HES was performed by Raman spectroscopy microimaging on M3 protocol renal graft biopsies. Statistical analyses were used to investigate the association between Raman data and graft characteristics. HES spectral signal was revealed negative in the control group, whereas it was positive in 40% of biopsies from the HES group. In the HES group, a stronger HES signal was associated with a lower risk of graft failure measured by the Kidney Donor Risk Index (KDRI) and was correlated with the allograft kidney function. Thus, HES accumulation in donor kidney, as probed by Raman biophotonic technique, is correlated with the quality of donor kidney and consequently the graft renal function and graft survival.