Capillary Filtration of Plasma is Accelerated During General Anesthesia: A Secondary Population Volume Kinetic Analysis.

How infusion fluids are distributed and eliminated is of importance to how much and how fast they should be administered. This manuscript applies population pharmacokinetic modeling to intravenous infusions of crystalloid fluid, which is a common therapy in hospital care and mandatory during surgery. The analysis was based on the hemodilution and urine output measured during and after 262 infusions of 1647 ± 461 mL (mean ± SD) of fluid over 30 min in adults.

Low-grade hemodilution improves the microcirculatory function in surgical patients.

Background: Excess fluid in the interstitium can adversely affect the microcirculation. We studied how gradual dilution of the blood plasma by crystalloid fluid influences microcirculatory variables and capillary filtration in 20 patients undergoing surgery.

Methods: Video recordings of the sublingual mucosal were made on four occasions during the surgery and compared with quasi-measurements of the capillary filtration rate using retrospective volume kinetic data collected over 5-10-minute periods during 262 infusion experiments with crystalloid fluid.

Is the NICE Guideline for maintenance fluid therapy in adults in hospital appropriate?

Background And Aims: The National Institute for Health and Care Excellence's (NICE) Guideline for Maintenance Fluid Therapy in Adults in Hospital is widely used, but the recommendations have not been evaluated properly. In this study, we investigated whether the recommendation of providing 25-30 mL/kg/day of fluid and 1 mmol/kg each of sodium and potassium is sufficient for human needs.

Methods: First, we calculated the distribution of fluid between the extracellular fluid volume (ECV) and intracellular fluid volume (ICV) during a cross-over infusion experiment where 12 volunteers received 25 mL/kg/day of either a high-sodium (154 mmol/L) or low-sodium (54 mmol/L) solution over 48 h.

Blood volume and hemodynamics during treatment of major hemorrhage with Ringer solution, 5% albumin, and 20% albumin: a single-center randomized controlled trial.

Background: Volume replacement with crystalloid fluid is the conventional treatment of hemorrhage. We challenged whether a standardized amount of 5% or 20% albumin could be a viable option to maintain the blood volume during surgery associated with major hemorrhage. Therefore, the aim of this study was to quantify and compare the plasma volume expansion properties of 5% albumin, 20% albumin, and Ringer-lactate, when infused during major surgery.

Detection of low urine output by measuring urinary biomarkers.

Background: Urine output < 1 L per 24 h is a clinical warning sign that requires attention from hospital staff, who should determine whether the low flow is due to low habitual intake of water or disease-induced dehydration. The incidence of this condition is unclear.

Methods: A cohort of 20 healthy volunteers (mean age 42 years, range 23-62 years) recorded their food and water intakes daily for 8 days.

Modulation of the capillary leakage by exogenous albumin in a rat model of endothelial glycocalyx damage.

Background: Endothelial glycocalyx (EG) plays a crucial role in maintaining the plasma proteins within the intravascular space.

Objective: We studied whether exogenous albumin protects the EG in an experimental model of EG enzymatic damage in rats.

Methods: Rats were divided into three groups of 10 animals that received (1) Evans blue (2) Evans blue + hyaluronidase, or (3) Evans blue + hyaluronidase + 20% human albumin via the tail vein.

Protection of the endothelium and endothelial glycocalyx by hydrogen against ischaemia-reperfusion injury in a porcine model of cardiac arrest.

Background: Hydrogen is a potent antioxidant agent that can easily be administered by inhalation. The aim of the study was to evaluate whether hydrogen protects the endothelial glycocalyx layer after successful cardiopulmonary resuscitation (CPR).

Methods: Fourteen anesthetized pigs underwent CPR after induced ventricular fibrillation.

Concentrated urine, low urine flow, and postoperative elevation of plasma creatinine: A retrospective analysis of pooled data.

Elevations of plasma creatinine are common after major surgery, but their pathophysiology is poorly understood. To identify possible contributing mechanisms, we pooled data from eight prospective studies performed in four different countries to study circumstances during which elevation of plasma creatinine occurs. We included 642 patients undergoing mixed major surgeries, mostly open gastrointestinal.

The kinetics of isotonic and hypertonic resuscitation fluids is dependent on the sizes of the body fluid volumes.

Background And Aims: The extracellular and intracellular fluid volumes (ECV and ICV) vary not only with age, gender, and body weight but also with the habitual intake of water. The present study examines whether the baseline variations in the ECV and ICV change the distribution and elimination of subsequently given infusion fluids.

Material And Methods: Twenty healthy male volunteers underwent 50 infusion experiments with crystalloid fluid for which the fluid volume kinetics was calculated based on frequent measurements of the hemodilution using mixed-effects modeling software.

Co-morbidity associated with development of severe COVID-19 before vaccine availability: a retrospective cohort study in the first pandemic year among the middle-aged and elderly in Jönköping county, Sweden.

Background: In preparation of future pandemics, it is important to recognise population-level determinants associated with development of severe illness before efficient vaccines and evidence-based therapeutic measures are available. The aim of this study was to identify pre-pandemic diagnoses recorded in a middle-aged and elderly population that were associated with development of severe COVID-19 during the first pandemic year.

Methods: A cohort study design was used.

Population Pharmacokinetics as a Tool to Reevaluate the Complex Disposition of Ethanol in the Fed and Fasted States.

The pharmacokinetics (PK) of ethanol are important in pharmacology and therapeutics because of potential drug-alcohol interactions as well as in forensic science when alcohol-related crimes are investigated. The PK of ethanol have been extensively studied since the 1930s, although some issues remain unresolved, such as the significance of first-pass metabolism, whether zero-order kinetics apply, and the effects of food on bioavailability. We took advantage of nonlinear mixed-effects modeling to describe blood-alcohol concentration (BAC) profiles derived from 3 published clinical studies involving oral, intraduodenal, and intravenous administration of ethanol with and without food.

Quantifying the daily intake of water from morning and spot urine samples; retrospective analysis of a clinical trial in volunteers.

Background: The hydration status can be indicated by biomarkers in the urine. However, the sensitivity and specificity of single measurements of biomarkers in morning urine and spot urine samples to quantify previous and current daily water ingestion is unclear.

Methods: The water content of food and liquid consumed by 20 volunteers (mean age 42 years) was calculated daily for two weeks.

Interstitial washdown during crystalloid fluid loading in graded hypovolemia -A retrospective analysis in volunteers.

Background: "Interstitial washdown" is an edema-preventing mechanism that implies a greater redistribution of interstitial albumin occurs whenever the capillary filtration is increased.

Objective: To study the effect of interstitial washdown on fluid distribution in normovolemic and hypovolemic volunteers.

Methods: Capillary filtration was increased by infusing 25 mL/kg Ringer's acetate intravenously over 30 min 10 male just after withdrawal of 0, 450, and 900 mL of blood.

Parasternal After Cardiac Surgery (PACS): a prospective, randomised, double-blinded, placebo-controlled trial study protocol for evaluating a continuous bilateral parasternal block with lidocaine after open cardiac surgery through sternotomy.

Background: Multimodal analgesia that provides optimal pain treatment with minimal side effects is important for optimal recovery after open cardiac surgery. Regional anaesthesia can be used to block noxious nerve signals. Because sternotomy causes considerable pain that lasts several days, a continuous nerve block is advantageous.

Renal Water Conservation and Plasma Creatinine in Colorectal Cancer Surgery: A Single-Group Clinical Study.

Elevation of plasma creatinine after surgery is associated with postoperative morbidity and mortality. We studied whether lengthy surgery might induce renal conservation of water strong enough to exceed the renal capacity to excrete creatinine. Colorectal cancer surgery was performed via laparoscopy in 126 patients.

Diuretic response to Ringer's solution is normal shortly after awakening from general anaesthesia: a retrospective kinetic analysis.

Background: The elimination of Ringer's solution is severely depressed during general anaesthesia, but the degree to which this continues postoperatively is poorly established.

Methods: An intravenous infusion of Ringer's acetate solution 20 ml kg was administered over 60 min in 12 patients undergoing laparoscopic cholecystectomy. Population kinetic analysis was performed based on repeated measurements of blood haemoglobin concentration and urinary excretion over 240 min regardless of when the operations were finished.

Kinetics of 5% and 20% albumin: A controlled crossover trial in volunteers.

Background: Albumin for intravenous infusion is marketed in two concentrations, 20% and 5%, but how they compare with regard to plasma volume expansion over time is unclear.

Methods: In a prospective crossover study, 12 volunteers received 3 ml kg of 20% albumin and, on another occasion, 12 ml kg of 5% albumin over 30 min. Hence, equivalent amounts of albumin were given.

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.

Endothelial glycocalyx damage in patients with severe COVID-19 on mechanical ventilation - A prospective observational pilot study.

Background: Coronavirus disease (COVID-19) associated endotheliopathy and microvascular dysfunction are of concern.

Objective: The objective of the present single-center observational pilot study was to compare endothelial glycocalyx (EG) damage and endotheliopathy in patients with severe COVID-19 (COVID-19 group) with patients with bacterial pneumonia with septic shock (non-COVID group).

Methods: Biomarkers of EG damage (syndecan-1), endothelial cells (EC) damage (thrombomodulin), and activation (P-selectin) were measured in blood on three consecutive days from admission to the intensive care unit (ICU).

Comparison between two solute equations and bioimpedance for estimation of body fluid volumes.

Background: The extracellular volume (ECV) and intracellular volume (ICV) estimated by bioimpedance analysis (BIA) deviates markedly from the textbook volumes of 20% and 40% of the body weight (BW). We estimated the transcellular exchange of water by calculating solute equilibriums after fluid challenges to examine whether the BIA or the textbook volumes are likely to be most correct.

Methods: Data was retrieved from 8 healthy male volunteers who received 25 mL/kg of Ringer's solution or 3-5 mL/kg of hypertonic (7.

Dehydration before Major Urological Surgery and the Perioperative Pattern of Plasma Creatinine: A Prospective Cohort Series.

Preoperative dehydration is usually found in 30-50% of surgical patients, but the incidence is unknown in the urologic population. We determined the prevalence of preoperative dehydration in major elective urological surgery and studied its association with postoperative outcome, with special attention to plasma creatinine changes. We recruited 187 patients scheduled for major abdominal urological surgery to participate in a single-center study that used the fluid retention index (FRI), which is a composite index of four urinary biomarkers that correlate with renal water conservation, to assess the presence of dehydration.

Plasma Volume Expansion and Fluid Kinetics of 20% Albumin During General Anesthesia and Surgery Lasting for More Than 5 Hours.

Background: Intraoperative administration of crystalloid for plasma volume expansion may be reduced by use of hyperoncotic albumin. However, the degree of plasma volume expansion with administration of 20% albumin is poorly quantitated. We estimated the amount of volume expansion attributable to 20% albumin administration in patients undergoing surgery for more than 5 hours.

Distribution of crystalloid fluid infused during onset of anesthesia-induced hypotension: a retrospective population kinetic analysis.

Background: Induction of anesthesia causes a drop in arterial pressure that might change the kinetics of infused crystalloid fluid. The aim of this report is to provide a mathematical view of how fluid distributes in this setting.

Methods: Data were retrieved from three studies where 76 patients (mean age 63 years, mean body weight 66 kg) had received approximately 1.

Isotonic saline causes greater volume overload than electrolyte-free irrigating fluids.

Objectives: Systemic absorption of the irrigating fluid used to flush the operating site is a potentially serious complication in several types of endoscopic operations. To increase safety, many surgeons have changed from a monopolar to a bipolar resection technique because 0.9% saline can then be used instead of electrolyte-free fluid for irrigation.