Plasma disappearance rate of albumin when infused as a 20% solution.

BACKGROUND: The transcapillary leakage of albumin is increased by inflammation and major surgery, but whether exogenous albumin also disappears faster is unclear. METHODS: An intravenous infusion of 3 mL/kg of 20% albumin was given over 30 min to 70 subjects consisting of 15 healthy volunteers, 15 post-burn patients, 15 patients who underwent surgery with minor bleeding, 10 who underwent surgery with major bleeding (mean, 1.1 L) and 15 postoperative patients. Blood Hb and plasma albumin were measured on 15 occasions over 5 h. The rate of albumin disappearance from the plasma was quantitated with population kinetic methodology and reported as the half-life (T1/2). RESULTS: No differences were observed for T1/2 between volunteers, post-burn patients, patients who underwent surgery with minor bleeding and postoperative patients. The T1/2 averaged 16.2 h, which corresponds to 3.8% of the amount infused per h. Two groups showed plasma concentrations of C-reactive protein of approximately 60 mg/L and still had a similarly long T1/2 for albumin. By contrast, patients undergoing surgery associated with major hemorrhage had a shorter T1/2, corresponding to 15% of the infused albumin per h. In addition, our analyses show that the T1/2 differ greatly depending on whether the calculations consider plasma volume changes and blood losses. CONCLUSION: The disappearance rate of the albumin in 20% preparations was low in volunteers, in patients with moderately severe inflammation, and in postoperative patients.

Perioperative fluid balance and major postoperative complications in surgery for advanced epithelial ovarian cancer.

OBJECTIVE: Appropriate fluid balance in the perioperative period is important as both hypo- and hypervolemia are associated with increased risk of complications. Women undergoing cytoreductive surgery (CRS) for advanced epithelial ovarian cancer (EOC) may have major fluid shifts. The optimal perioperative fluid balance in these women is yet to be determined. Our objective was to investigate the association between perioperative fluid balance and major postoperative complications. METHODS: Women with advanced stage EOC who underwent surgery at Karolinska University Hospital, Stockholm, Sweden were identified from the institutional database. Women subjected to surgery with curative intent were included in the analysis. Additional data were retrieved from medical records. The association between perioperative fluid balance and major postoperative complications was investigated by multivariable regression and adjusted for predefined confounders. RESULTS: Of the 270 women identified in the institutional database during 2014-2017, 184 women were included in the analyses. Of these women, 22% (n = 40) experienced a major postoperative complication. The fully adjusted odds of major postoperative complications increased when perioperative fluid balance exceeded >3000 mL, (Odds Ratio (OR) 4.85, 95% Confidence Interval (CI) 1.23-19.2, p = 0.02) and > 5000 mL (OR 33.7, 95% CI 4.13-275, p < 0.01). There was no association between negative fluid balance and major postoperative complications (OR 3.33, 95% CI 0.25-44.1, p = 0.36). CONCLUSIONS: Fluid balance >3000 mL perioperatively during surgery for advanced EOC increased the odds of major postoperative complications. Management of perioperative fluid balance in advanced EOC surgery remains a challenge.

Surgery performed later in the week is associated with inferior survival in advanced ovarian cancer.

BACKGROUND: Complete macroscopic resection without any residual tumour after completion of surgery is a strong prognostic factor in advanced epithelial ovarian cancer (EOC). It has previously been reported that surgery performed later in the week is associated with failure to achieve complete macroscopic resection. Our objective was to examine if weekday of surgery influences oncologic outcome. MATERIALS AND METHODS: This population-based observational study included 100% of all women diagnosed with advanced-stage invasive epithelial ovarian cancer between 2009-2011 and 2014-2016 in the Stockholm/Gotland County of Sweden. The association between weekday of surgery and survival was analysed with proportional hazards regression yielding hazard ratios (HR) with 95% confidence intervals (CI), adjusted for predefined confounders. RESULTS: Out of 1066 identified women, 524 with advanced stage EOC treated with surgery were included in the final analysis. Surgery performed Wednesday to Thursday was associated with an increased hazard of death (HR 1.28, 95% CI 1.04-1.58, p-value 0.02). The trend of the hazard of surgery performed throughout the week from Monday through Thursday was also significant (p = 0.01). CONCLUSION: The increased mortality associated with surgery that is performed later in the week suggests that surgery for advanced ovarian cancer is best conducted early in the week.

Surgery performed later in the week is associated with failure to achieve complete radical surgical resection in advanced ovarian cancer.

Background: The surgical treatment of advanced ovarian cancer aims to resect all visible tumor to no gross residual, these procedures are often extensive with need of prolonged attention to detail. Our objective was to investigate the association between week-day of surgery, time of year (season) when surgery was performed and non-radical surgery (surgical failure) in advanced ovarian cancer.Material and methods: Women diagnosed with primary invasive epithelial ovarian cancer in the Stockholm/Gotland Region, Sweden were identified in the regional Swedish Quality Registry of Gynecologic Cancer (SQRGC). Data of all women with International Federation of Gynecology and Obstetrics (FIGO) stages III and IV were validated against the National Cancer Registry. Women subjected to surgery with curative intent were selected and included in the analysis. Uni- and multivariable regression analyses were performed.Results: Out of 538 women identified in the SQRGC-string ovary between 2014 and 2016, 240 were eligible for analysis. In 29% of women, complete radical resection was not achieved. There was a significant trend of increased non-radical resection when surgery was performed from Monday through Thursday (p = .03). The adjusted odds of non-radical surgery increased if surgery was performed on Thursday rather than Monday (Odds Ratio (OR) 3.04, 95% Confidence Interval (CI) 1.05-8.79, p = .04). Surgery performed during summer compared to the rest of the year, did not significantly increase the adjusted odds of non-radical surgery (OR 1.92, 95% CI 0.91-4.07, p = .09).Conclusion: Complete surgical resection of tumor is one of the strongest prognostic factors for survival in advanced epithelial ovarian cancer. For this reason, advanced ovarian cancer surgery should be scheduled early in the week.

Fluid volume kinetics of 20% albumin.

AIMS: A population kinetic model was developed for the body fluid shifts occurring when 20% albumin is given by intravenous infusion. The aim was to study whether its efficacy to expand the plasma volume is impaired after major surgery. METHODS: An intravenous infusion of 3 mL/kg 20% albumin over 30 minutes was given to 15 volunteers and to 15 patients on the 1st day after major open abdominal surgery. Blood samples and urine were collected during 5 hours. Mixed-effect modelling software was used to develop a fluid volume kinetic model, using blood haemoglobin and urine excretion the estimate body fluid shifts, to which individual-specific covariates were added in sequence. RESULTS: The rise in plasma albumin expanded the plasma volume in excess of the infused volume by relocating noncirculating fluid (rate constant k21 ), but it also increased losses of fluid from the kinetic system (kb ). The balance between k21 and kb maintained the rise in plasma albumin and plasma volume at a virtual steady-state for almost 2 hours. The rate constant for urinary excretion (k10 ) was slightly reduced by the preceding surgery, by a marked rise in plasma albumin, and by a high preinfusion urinary concentration of creatinine. The arterial pressure, body weight, and plasma concentrations of C-reactive protein and shedding products of the endothelial glycocalyx layer (syndecan-1, heparan sulfate, and hyaluronic acid) did not serve as statistically significant covariates. CONCLUSIONS: There were no clinically relevant differences in the kinetics of 20% albumin between postoperative patients and volunteers.

Long Intravascular Persistence of 20% Albumin in Postoperative Patients.

BACKGROUND: Albumin may persist intravascularly for a shorter time in patients after major surgery than in healthy volunteers due to a surgery-induced breakdown (shedding) of the endothelial glycocalyx layer. METHODS: In this nonrandomized clinical trial, an IV infusion of 3 mL/kg of 20% albumin was given at a constant rate during 30 minutes to 15 patients on the first day after major open abdominal surgery (mean operating time 5.9 h) and to 15 conscious volunteers. Blood samples and urine were collected during 5 h and mass balance calculations used to estimate the half-lives of the administered albumin molecules and the induced plasma volume expansion, based on measurements of hemodilution and the plasma albumin concentration. RESULTS: At the end of the infusions, albumin had diluted the plasma volume by 13.3% ± 4.9% (mean ± SD) in the postoperative patients and by 14.2% ± 4.8% in the volunteers (mean difference -0.9, 95% CI, -4.7 to 2.9; 1-way ANOVA P = .61), which amounted to twice the infused volume. The intravascular half-life of the infused albumin molecules was 9.1 (5.7-11.2) h in the surgical patients and 6.0 (5.1-9.0) h in the volunteers (Mann-Whitney U test, P = .26; geometric mean difference 1.2, 95% CI, 0.8-2.0). The half-life of the plasma volume expansion was 10.3 (5.3-17.6; median and interquartile range) h in the surgical patients and 7.6 (3.5-9.0) h in the volunteers (P = .10; geometric mean difference 1.5, 95% CI, 0.8-2.8). All of these parameters correlated positively with the body mass index (correlation coefficients being 0.42-0.47) while age and sex did not affect the results. CONCLUSIONS: Twenty percent albumin caused a long-lasting plasma volume expansion of similar magnitude in postoperative patients and volunteers.

Diuretic responses to Ringer's solution and 20% albumin at different arterial pressures.

Intravenous volume loading is a common treatment when hypovolemia is a potential cause of oliguria. We studied whether the effectiveness of Ringer's solution and 20% albumin in inducing diuresis differs depending on the mean arterial pressure (MAP). For this purpose, volume kinetic analysis was performed based on urine output and hemoglobin-derived plasma dilution obtained during and after 136 infusions of Ringer and 85 infusions of 20% albumin. Covariance analysis quantified the diuretic response at different arterial pressures. The results show that the diuretic response to a known plasma volume expansion was greater for Ringer's solution above a MAP of 70 mmHg, while 20% albumin was significantly more effective at lower pressures (p < 0.03). Simulations of the urinary output in response to infusion of a predefined fluid volume yielded superior efficacy for 20% albumin when the MAP was low, while Ringer's was similarly effective when the MAP averaged 100 mmHg. In conclusion, urine output in response to plasma volume expansion with 20% albumin was similar to, or even stronger, than that of Ringer's solution when the MAP was below 70 mmHg.

Biomarkers of endothelial injury in plasma are dependent on kidney function.

BACKGROUND: Injury (shedding) of the endothelial glycocalyx layer, which alters local blood flow and microvascular permeability, is assessed by measuring components of this layer in circulating blood. The influence of renal function on their concentrations is unknown. METHODS: Plasma and urine concentrations of three shedding products (syndecan-1, hyaluronic acid, and heparan sulfate) and creatinine were measured over 5 hours in 15 healthy volunteers and 15 postoperative patients; this guaranteed a spread of kidney functions. Renal clearances were calculated. RESULTS: Low renal clearances of syndecan-1 (mean 3.5 mL/min) and hyaluronic acid (0.8 mL/min) correlated inversely with the 6-fold variability in the plasma concentrations of these substances (r = - 0.45 and- 0.49). Low creatinine clearance correlated inversely (r = - 0.60) and plasma creatinine directly (r = 0.52) with the two-fold variability in heparan sulfate, which was the only shedding substance that also correlated with C-reactive protein (r = 0.51) and, therefore, showed higher concentrations after surgery. CONCLUSIONS: The present explorative study suggests that a 6-fold variability in the plasma concentrations of three commonly measured endothelial shedding products can be understood by the kidney's ability to excrete them. This finding has implications when interpreting results of studies where shedding is assessed.