Hemodynamic Responses to Crystalloid and Colloid Fluid Boluses during Noncardiac Surgery.

BACKGROUND: Colloids are thought to sustain blood pressure and cardiac index better than crystalloids. However, the relative effects of intraoperative hydroxyethyl starch and crystalloid administration on the cardiac index and blood pressure remain unclear. This study therefore tested in this subanalysis of a previously published large randomized trial the hypothesis that intraoperative goal-directed colloid administration increases the cardiac index more than goal-directed crystalloid administration. Further, the effects of crystalloid and colloid boluses on blood pressure were evaluated. METHODS: This planned subanalysis of a previous trial analyzed data from 973 patients, of whom 480 were randomized to colloids and 493 were randomized to crystalloids. Fluid administration was guided by esophageal Doppler. The primary outcome was the time-weighted average cardiac index during surgery between the colloid and crystalloid group. The secondary outcomes were the cardiac index just after bolus administration, time elapsed between boluses, and the average real variability during surgery. The study recorded cardiac index, corrected flow time, and blood pressure at 10-min intervals, as well as before and after each bolus. RESULTS: Time-weighted average of cardiac index over the duration of anesthesia was only slightly greater in patients given colloid than crystalloid, with the difference being just 0.20 l · min-1 · m-2 (95% CI, 0.11 to 0.29; P < 0.001). However, the hazard for needing additional boluses was lower after colloid administration (hazard ratio [95% CI], 0.60 [0.55 to 0.66]; P < 0.001) in a frailty time-to-event model accounting for within-subject correlation. The median [quartiles] number of boluses per patient was 4 [2, 6] for colloids and 6 [3, 8] for crystalloids, with a median difference (95% CI) of -1.5 (-2 to -1; P < 0.001). The average real mean arterial pressure variability did not differ significantly between the groups (difference in means [95% CI] of -0.03 (-0.07 to 0.02) mmHg, P = 0.229). CONCLUSIONS: There were not clinically meaningful differences in the cardiac index or mean pressure variability in patients given goal-directed colloid and crystalloids. As might be expected from longer intravascular dwell time, the interval between boluses was longer with colloids. However, on a case basis, the number of boluses differed only slightly. Colloids do not appear to provide substantial hemodynamic benefit.

Norepinephrine potentiates the efficacy of volume expansion on mean systemic pressure in septic shock.

BACKGROUND: Through venous contraction, norepinephrine (NE) increases stressed blood volume and mean systemic pressure (Pms) and exerts a "fluid-like" effect. When both fluid and NE are administered, Pms may not only result from the sum of the effects of both drugs. Indeed, norepinephrine may enhance the effects of volume expansion: because fluid dilutes into a more constricted, smaller, venous network, fluid may increase Pms to a larger extent at a higher than at a lower dose of NE. We tested this hypothesis, by mimicking the effects of fluid by passive leg raising (PLR). METHODS: In 30 septic shock patients, norepinephrine was decreased to reach a predefined target of mean arterial pressure (65-70 mmHg by default, 80-85 mmHg in previously hypertensive patients). We measured the PLR-induced increase in Pms (heart-lung interactions method) under high and low doses of norepinephrine. Preload responsiveness was defined by a PLR-induced increase in cardiac index ≥ 10%. RESULTS: Norepinephrine was decreased from 0.32 [0.18-0.62] to 0.26 [0.13-0.50] µg/kg/min (p < 0.0001). This significantly decreased the mean arterial pressure by 10 [7-20]% and Pms by 9 [4-19]%. The increase in Pms (∆Pms) induced by PLR was 13 [9-19]% at the higher dose of norepinephrine and 11 [6-16]% at the lower dose (p < 0.0001). Pms reached during PLR at the high dose of NE was higher than expected by the sum of Pms at baseline at low dose, ∆Pms induced by changing the norepinephrine dose and ∆Pms induced by PLR at low dose of NE (35.6 [11.2] mmHg vs. 33.6 [10.9] mmHg, respectively, p < 0.01). The number of preload responders was 8 (27%) at the high dose of NE and 15 (50%) at the low dose. CONCLUSIONS: Norepinephrine enhances the Pms increase induced by PLR. These results suggest that a bolus of fluid of the same volume has a greater haemodynamic effect at a high dose than at a low dose of norepinephrine during septic shock.

Umbilical vein injection for management of retained placenta.

BACKGROUND: Retained placenta is a common complication of pregnancy affecting 1% to 6% of all births. If a retained placenta is left untreated, spontaneous delivery of the placenta may occur, but there is a high risk of bleeding and infection. Manual removal of the placenta (MROP) in an operating theatre under anaesthetic is the usual treatment, but is invasive and may have complications. An effective non-surgical alternative for retained placenta would potentially reduce the physical and psychological trauma of the procedure, and costs. It could also be lifesaving by providing a therapy for settings without easy access to modern operating theatres or anaesthetics. Injection of uterotonics into the uterus via the umbilical vein and placenta is an attractive low-cost option for this. This is an update of a review last published in 2011. OBJECTIVES: To assess the use of umbilical vein injection (UVI) of saline solution with or without uterotonics compared to either expectant management or with an alternative solution or other uterotonic agent for retained placenta. SEARCH METHODS: For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (14 June 2020), and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing UVI of saline or other fluids (with or without uterotonics), either with expectant management or with an alternative solution or other uterotonic agent, in the management of retained placenta. We considered quasi-randomised, cluster-randomised, and trials reported only in abstract form. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. We assessed the certainty of the evidence using the GRADE approach. We calculated pooled risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs), and presented results using 'Summary of findings' tables. MAIN RESULTS: We included 24 trials (n = 2348). All included trials were RCTs, one was quasi-randomised, and none were cluster-randomised. Risk of bias was variable across the included studies. We assessed certainty of evidence for four comparisons: saline versus expectant management, oxytocin versus expectant management, oxytocin versus saline, and oxytocin versus plasma expander. Evidence was moderate to very-low certainty and downgraded for risk of bias of included studies, imprecision, and inconsistency of effect estimates. Saline solution versus expectant management There is probably little or no difference in the incidence of MROP between saline and expectant management (RR 0.93, 95% CI 0.80 to 1.10; 5 studies, n = 445; moderate-certainty evidence). Evidence for the following remaining primary outcomes was very-low certainty: severe postpartum haemorrhage 1000 mL or greater, blood transfusion, and infection. There were no events reported for maternal mortality or postpartum anaemia (24 to 48 hours postnatal). No studies reported addition of therapeutic uterotonics. Oxytocin solution versus expectant management UVI of oxytocin solution might slightly reduce in the need for manual removal compared with expectant management (mean RR 0.73, 95% CI 0.56 to 0.95; 7 studies, n = 546; low-certainty evidence). There may be little to no difference between the incidence of blood transfusion between groups (RR 0.81, 95% CI 0.47 to 1.38; 4 studies, n = 339; low-certainty evidence). There were no maternal deaths reported (2 studies, n = 93). Evidence for severe postpartum haemorrhage of 1000 mL or greater, additional uterotonics, and infection was very-low certainty. There were no events for postpartum anaemia (24 to 48 hours postnatal). Oxytocin solution versus saline solution UVI of oxytocin solution may reduce the use of MROP compared with saline solution, but there was high heterogeneity (RR 0.82, 95% CI 0.69 to 0.97; 14 studies, n = 1370; I² = 54%; low-certainty evidence). There were no differences between subgroups according to risk of bias or oxytocin dose for the outcome MROP. There may be little to no difference between groups in severe postpartum haemorrhage of 1000 mL or greater, blood transfusion, use of additional therapeutic uterotonics, and antibiotic use. There were no events for postpartum anaemia (24 to 48 hours postnatal) (very low-certainty evidence) and there was only one event for maternal mortality (low-certainty evidence). Oxytocin solution versus plasma expander One small study reported UVI of oxytocin compared with plasma expander (n = 109). The evidence was very unclear about any effect on MROP or blood transfusion between the two groups (very low-certainty evidence). No other primary outcomes were reported. For other comparisons there were little to no differences for most outcomes examined. However, there was some evidence to suggest that there may be a reduction in MROP with prostaglandins in comparison to oxytocin (4 studies, n = 173) and ergometrine (1 study, n = 52), although further large-scale studies are needed to confirm these findings. AUTHORS' CONCLUSIONS: UVI of oxytocin solution is an inexpensive and simple intervention that can be performed when placental delivery is delayed. This review identified low-certainty evidence that oxytocin solution may slightly reduce the need for manual removal. However, there are little or no differences for other outcomes. Small studies examining injection of prostaglandin (such as dissolved misoprostol) into the umbilical vein show promise and deserve to be studied further.

A prospective randomized open-label trial on the comparative effects of 6% hydroxyethyl starch 130/0.4 versus polyionic isotonic crystalloids on coagulation parameters in dogs with spontaneous hemoperitoneum.

OBJECTIVE: To evaluate the effects of 6% hydroxyethyl starch 130/0.4 (HES) and a polyionic isotonic crystalloid (CRYS) on standard coagulation tests and rotational thromboelastometry (ROTEM) in dogs with spontaneous hemoperitoneum (SHP). DESIGN: Prospective randomized open-label clinical study. SETTING: University teaching hospital. ANIMALS: Forty-two client-owned dogs presented with SHP. INTERVENTIONS: Dogs diagnosed with SHP and hypovolemic shock were randomly allocated to receive HES (10 mL/kg, n = 22) or CRYS (30 mL/kg, n = 20) intravenously over 20 minutes for hemodynamic stabilization. MEASUREMENTS AND MAIN RESULTS: Parameters measured before (T0 ) and after (T1 ) treatment were HCT, platelet counts, prothrombin time, activated partial thromboplastin time, fibrinogen concentrations, and extrinsic activated (EXTEM), intrinsic activated (INTEM), and extrinsic activated with platelet inhibition ROTEM assays. Data were analyzed as absolute values and as the percentage change from T0 to T1 . No significant differences between groups were detected in any variable at T0 , and for HCT, platelet counts, prothrombin time, activated thromboplastin time, and fibrinogen concentrations at T1 . Clot formation time in EXTEM was significantly prolonged (P = 0.037), and maximum clot firmness was significantly decreased (P = 0.038) in the HES group compared to the CRYS group at T1 . The percentage change in EXTEM clotting time (P = 0.012) and INTEM clot formation time (P = 0.031) was greater after HES than CRYS. Lysis indices remained at 100% for all ROTEM assays in both groups. CONCLUSION: Compared to a 3-fold volume of CRYS, administration of HES was associated with impairment in ROTEM parameters in dogs with SHP, but no evidence of hyperfibrinolysis was detected.

Intraoperative Intravascular Effect of Lactated Ringer's Solution and Hyperoncotic Albumin During Hemorrhage in Cystectomy Patients.

BACKGROUND: The intraoperative effect of 20% albumin on plasma volume during surgery involving major blood loss has not been explored extensively due to methodological difficulties. Crystalloids poorly expand the plasma volume, and using a colloid might then be a way to avoid fluid overload. As doubts have been raised about synthetic colloids, albumin solutions are currently used more extensively. This study presents a methodological development showing how plasma volume expansion can be studied in surgical settings with the coinfusion of 20% albumin and lactated Ringer's solution. METHODS: In this single-arm, single-center feasibility study, an intravenous (i.v.) infusion of 3 mL·kg·BW-1 of 20% albumin was administered over 30 minutes to 23 cystectomy patients during the bleeding phase in addition to lactated Ringer's solution to correct blood loss. Blood samples were measured at regular intervals over a period of 300 minutes to estimate the blood volume expansion resulting from simultaneous infusions of lactated Ringer's and 20% albumin solutions, using a regression equation and the area under the volume-time curve method. RESULTS: Mean hemorrhage was 974 mL (standard deviation [SD] ± 381). The regression method showed strong correlation (r2 = 0.58) between blood loss minus blood volume expansion and the independent effects of the infused volume of lactated Ringer's and 20% albumin solutions. The mean plasma volume expansion attributable to the infusion of lactated Ringer's solution amounted to 0.38 (95% confidence interval [CI], 0.31-0.49) of the infused volume; for the 20% albumin, it was 1.94 mL/mL (95% CI, 1.41-2.46 mL/mL) over 5 hours on average (regression method). The mean within-patient change was 0.20 mL/mL (± 0.06 mL/mL) for the lactated Ringer's solution and 2.20 mL/mL (±1.31 mL/mL) for the 20% albumin using the area under the volume-time curve method. CONCLUSIONS: Blood volume expansion averaged 1.9-2.2 times the infused volume of 20% albumin during surgery associated with hemorrhage of around 1000 mL. This effect was long standing and approximately 5 times stronger than for the lactated Ringer's solution. Twenty percent albumin boosts the plasma volume expansion of lactated Ringer's solution to as high as 40% of the infused volume on the average, which is an effect that lasts at least 5 hours.

Impact of Hyperoncotic Albumin on Duration of Vasopressor Support in Septic Shock: A Propensity Score-Matched Analysis.

BACKGROUND: While albumin has not been shown to reduce mortality in sepsis and septic shock, a tertiary analysis of a large trial suggested that it may reduce the duration of vasopressor use in septic shock. OBJECTIVE: We sought to test if 25% albumin administration was associated with reduced cumulative vasopressor use in septic shock in a real-world setting. METHODS: This was a retrospective, propensity score-matched cohort study of septic shock in which patients receiving albumin were compared with a matched cohort of those not receiving albumin. The primary outcome was days alive and free of vasopressors. RESULTS: The matched cohort included 335 patients who received albumin and 335 who did not. The days alive and free of vasopressors were similar between the albumin and no albumin groups: 17.4 (0-24.8) versus 19.4 (0-25.3); P = 0.160. Similarly, in-hospital mortality was no different between groups (46.9% vs 44.8%; P = 0.587). Receipt of albumin was associated with fewer ventilator-free and intensive care unit (ICU)-free days: 0 (0-19) versus 11 (0-23), P = 0.007, and 0 (0-18) versus 10.6 (0-22.1), P = 0.002, respectively. CONCLUSION AND RELEVANCE: Albumin use in septic shock was not associated with additional days alive and free of vasopressors or in-hospital mortality. The finding of fewer ventilator- and ICU-free days may reflect selection of patients who were critically ill for longer periods of time before or after albumin administration. Additional study is needed to clarify the impact that timing may have on the effectiveness of albumin in septic shock.

Evaluation of the effects of hydroxyethyl starch (130/0.4) administration as a constant rate infusion on plasma colloid osmotic pressure in hypoabluminemic dogs.

OBJECTIVE: To evaluate the effects of 2 constant rate infusions of hydroxyethyl starch (HES) 130/0.4 on plasma colloid osmotic pressure (COP) in hypoalbuminemic dogs. DESIGN: Prospective, randomized clinical trial. ANIMALS: A total of 24 client-owned dogs. INTERVENTIONS: Hypoalbuminemic euvolemic dogs (albumin < 20 g/L [<2 g/dL]) with normal perfusion parameters requiring IV fluid therapy were enrolled. In addition to crystalloid, HES 130/0.4 was administered as a constant rate infusion over 24 hours at 1 mL/kg/h (group 1, n = 15) or at 2 mL/kg/h (group 2, n = 9), in order to support plasma COP. Before infusion, a blood sample was collected to perform CBC, serum electrophoresis, and serologic tests for some infective diseases. Plasma COP, albumin concentration, PCV, and total plasma protein concentration were evaluated serially at baseline (T0) and then at 6, 12, and 24 hours after the start of infusion, and a multilevel model was performed for these parameters to detect statistically significant differences between the 2 groups. MEASUREMENT AND MAIN RESULTS: Twenty-four dogs were included. No statistically significant differences in COP were found between the 2 groups; however, a high level of variability has been identified within the single individual. Among the other laboratory analyses, PCV was significantly decreased in group 1 at T12 and T24 compared with T0 (P < 0.001) and total plasma protein concentration was significantly increased in group 2 at T12 and T24 compared with T0 (P < 0.008). CONCLUSION: No significant effect on plasma COP was found following infusion with HES 130/0.4 at doses of 1 mL/kg/h and 2 mL/kg/h for 24 hours to hypoalbuminemic dogs. The administered concomitant dose of crystalloids, underlying disease, and small sample size were all potential confounding factors.

Impact of 6% balanced hydroxyethyl starch following cardiopulmonary bypass on renal function: a retrospective study.

BACKGROUND: We aimed to evaluate the effect of limited volume of hydroxyethyl starch (HES) administration on postoperative renal function in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). METHODS: One thousand six hundred fifty-seven patients undergoing cardiac surgery under CPB over two years were included. The patients were divided according to the amount of HES administrated during the first 2 days post-surgery; moderate dose HES (≥20 ml/kg) versus low dose HES (< 20 ml/kg). Outcomes were compared by using inverse probability weighting. RESULTS: Incidence of acute kidney injury (AKI) was higher in the moderate HES group (p = .02). However, new renal replacement therapy (RRT) (P = .30) and early mortality (p = .97) was similar between the groups. When adjusted, the moderate HES use was associated with AKI (OR, 1.66; 95% CI, 1.12-2.44; p = .01), but did not increase the risk of new RRT (OR, 1.27; 95% CI, 0.71-2.18; p = .40) or early mortality (HR, 0.73; 95% CI, 0.29-1.81; p = .50). CONCLUSIONS: The moderate dose administration of HES (≥20 ml/kg) in the postoperative period following cardiac surgery might be associated with the risk of AKI. However, it was not associated with serious adverse outcomes such as new RRT or mortality. Further randomized controlled studies are needed to validate study results.

The effect of intraoperative goal-directed crystalloid versus colloid administration on perioperative inflammatory markers - a substudy of a randomized controlled trial.

BACKGROUND: Excessive perioperative fluid administration may result in iatrogenic endothelial dysfunction and tissue edema, transducing inflammatory markers into the bloodstream. Colloids remain longer in the circulation, requiring less volume to reach similar hemodynamic endpoints compared to crystalloids. Thus, we tested the hypothesis that a goal-directed colloid regimen attenuates the inflammatory response compared to a goal-directed crystalloid regime. METHODS: Patients undergoing moderate- to high-risk open abdominal surgery were randomly assigned to goal-directed lactated Ringer's solution (n = 58) or a hydroxyethyl starch 6% 130/0.4 (n = 62) fluid regimen. Our primary outcome was perioperative levels of pro- and anti-inflammatory cytokines. Secondary outcome was perioperative levels of white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT) and lipopolysaccharide-binding protein (LBP). Measurements were performed preoperatively, immediate postoperatively, on postoperative day one, two and four. RESULTS: The areas under the curve of Interleukin (IL) 6 (p = 0.60), IL 8 (p = 0.46), IL 10 (p = 0.68) and tumor necrosis factor α (p = 0.47) levels did not differ significantly between the groups. WBC, CRP and PCT values were also comparable. LBP, although significantly higher in the crystalloid group, remained in the normal range. Patients assigned to crystalloids received a median (IQR) amount of 3905 mL (2880-5288) of crystalloid. Patients assigned to colloids received 1557 mL (1207-2116) of crystalloid and 1250 mL (750-1938) of colloid. CONCLUSION: Cytokine and inflammatory marker levels did not differ between goal-directed crystalloid and colloid administration after moderate to high-risk abdominal surgery. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT00517127 ). Registered 16th August 2007.

Hydroxyethyl starch for perioperative goal-directed fluid therapy in 2020: a narrative review.

BACKGROUND: Perioperative fluid management - including the type, dose, and timing of administration -directly affects patient outcome after major surgery. The objective of fluid administration is to optimize intravascular fluid status to maintain adequate tissue perfusion. There is continuing controversy around the perioperative use of crystalloid versus colloid fluids. Unfortunately, the importance of fluid volume, which significantly influences the benefit-to-risk ratio of each chosen solution, has often been overlooked in this debate. MAIN TEXT: The volume of fluid administered during the perioperative period can influence the incidence and severity of postoperative complications. Regrettably, there is still huge variability in fluid administration practices, both intra-and inter-individual, among clinicians. Goal-directed fluid therapy (GDFT), aimed at optimizing flow-related variables, has been demonstrated to have some clinical benefit and has been recommended by multiple professional societies. However, this approach has failed to achieve widespread adoption. A closed-loop fluid administration system designed to assist anesthesia providers in consistently applying GDFT strategies has recently been developed and tested. Such an approach may change the crystalloid versus colloid debate. Because colloid solutions have a more profound effect on intravascular volume and longer plasma persistence, their use in this more "controlled" context could be associated with a lower fluid balance, and potentially improved patient outcome. Additionally, most studies that have assessed the impact of a GDFT strategy on the outcome of high-risk surgical patients have used hydroxyethyl starch (HES) solutions in their protocols. Some of these studies have demonstrated beneficial effects, while none of them has reported severe complications. CONCLUSIONS: The type and volume of fluid used for perioperative management need to be individualized according to the patient's hemodynamic status and clinical condition. The amount of fluid given should be guided by well-defined physiologic targets. Compliance with a predefined hemodynamic protocol may be optimized by using a computerized system. The type of fluid should also be individualized, as should any drug therapy, with careful consideration of timing and dose. It is our perspective that HES solutions remain a valid option for fluid therapy in the perioperative context because of their effects on blood volume and their reasonable benefit/risk profile.

Stimulus-specific functional remodeling of the left ventricle in endurance and resistance-trained men.

Left ventricular (LV) structural remodeling following athletic training has been evidenced through training-specific changes in wall thickness and geometry. Whether the LV response to changes in hemodynamic load also adapts in a training-specific manner is unknown. Using echocardiography, we examined LV responses of endurance-trained (n = 15), resistance-trained (n = 14), and nonathletic men (n = 13) to 1) 20, 40, and 60% one repetition-maximum (1RM), leg-press exercise and 2) intravascular Gelofusine infusion (7 mL/kg) with passive leg raise. While resting heart rate was lower in endurance-trained participants versus controls (P = 0.001), blood pressure was similar between groups. Endurance-trained individuals had lower wall thickness but greater LV mass relative to body surface area versus controls, with no difference between resistance-trained individuals and controls. Leg press evoked a similar increase in blood pressure; however, resistance-trained participants preserved stroke volume (SV; -3 ± 8%) versus controls at 60% 1RM (-15 ± 7%, P = 0.001). While the maintenance of SV was related to the change in longitudinal strain across all groups (R = 0.537; P = 0.007), time-to-peak strain was maintained in resistance-trained but delayed in endurance-trained individuals (1 vs. 12% delay; P = 0.021). Volume infusion caused a similar increase in end-diastolic volume (EDV) and SV across groups, but leg raise further increased EDV only in endurance-trained individuals (5 ± 5 to 8 ± 5%; P = 0.018). Correlation analysis revealed a relationship between SV and longitudinal strain following infusion and leg raise (R = 0.334, P = 0.054); however, we observed no between-group differences in longitudinal myocardial mechanics. In conclusion, resistance-trained individuals better maintained SV during pressure loading, whereas endurance-trained individuals demonstrated greater EDV reserve during volume loading. These data provide novel evidence of training-specific LV functional remodeling.NEW & NOTEWORTHY Training-specific functional remodeling of the LV in response to different loading conditions has been recently suggested, but not experimentally tested in the same group of individuals. Our data provide novel evidence of a dichotomous, training-specific LV adaptive response to hemodynamic pressure or volume loading.

Blood acid-base, haematological and haemostatic effects of hydroxyethyl starch (130/0.4) compared to succinylated gelatin colloid infusions in normovolaemic dogs.

Synthetic colloids are commonly administered to dogs to treat absolute or relative hypovolaemia. Voluven® (tetrastarch 130/0.4) and Gelofusine® (succinylated gelatin) are available to veterinarians in South Africa. In humans, use of these products has caused acid-base derangements, changes in haematology and impaired haemostasis. We aimed to investigate these effects in healthy normovolaemic dogs. Eight healthy adult beagle dogs underwent a cross-over study, receiving Voluven® or Gelofusine® (10 mL/kg/h for 120 min) once each with a 14-day washout between treatments. Dogs were premedicated with dexmedetomidine (10 µg/kg intramuscularly). Anaesthesia was induced with propofol and the dogs were maintained with isoflurane-in-oxygen. The anaesthetised dogs were connected to a multi-parameter monitor to monitor physiological parameters throughout. Catheters placed in a jugular vein and dorsal metatarsal artery allowed sampling of venous and arterial blood. Blood was collected immediately prior to commencement of colloid infusion, after 60 min infusion and at the end of infusion (120 min) to allow for arterial blood gas analysis, haematology and coagulation testing (activated partial thromboplastin time [aPTT], prothrombin time [PT] and thromboelastography [TEG]). There was no effect, between treatments or over time, on blood pH. The haemoglobin concentration, erythrocyte count and haematocrit decreased significantly over time (all p 0.01), with no differences between treatments, and remained within normal clinical ranges. There were no differences between treatments or over time for the TEG, aPTT and PT tests of haemostasis. At the dose studied, Voluven® and Gelofusine® had comparably negligible effects on blood acid-base balance and coagulation in normovolaemic dogs.

Cardiovascular Volume Reserve in Patients with Heart Failure and Reduced Ejection Fraction.

This study aimed to investigate the relationship between intravascular volume and intracardiac filling pressures in stable HF patients with reduced ejection fraction (HFrEF). A total of 40 HFrEF patients (LVEF 36 ± 10%) (10 subjects with a pulmonary artery catheter) underwent intravascular volume expansion with 1 L hydroxyl-ethyl-starch over 3 h with coinciding intravascular volume measurements (technetium (99 tc)-labeled red blood cell technique). Intravascular blood volume increased from 5.0 ± 1.0 L to 5.7 ± 1.0 L (p < 0.0001). No change in clinical status, echocardiographic indices, or cardiac filling pressures was noticed. Invasively measured right atrial pressure and pulmonary arterial wedge pressure increased significantly immediately after start of infusion (4 ± 2 mmHg to 8 ± 4 mmHg; p = 0.01 and 10 ± 3 mmHg to 15 ± 6 mmHg; p = 0.01, respectively), decreased afterwards, and remained stable for 3 h (6 ± 2 mmHg and 14 ± 4 mmHg, respectively). The accuracy of cardiac filling pressure estimates to predict intravascular volume expansion was low (all AUC < 0.65).

Effects of anaesthesia-induced hypotension and phenylephrine on plasma volume expansion by hydroxyethyl starch: A randomised controlled study.

BACKGROUND: Changes in blood haemoglobin concentration indicate plasma volume expansion following hydroxyethyl starch (HES) infusion, but may be affected by vascular tone and HES-induced shedding of the endothelial surface layer (ESL). We hypothesised that anaesthesia-induced hypotension enhances changes in plasma volume as assessed by blood haemoglobin concentration (ΔPVHb , %) following HES infusion. METHODS: Fifty-two patients undergoing abdominal surgery were randomised to receive a continuous infusion of saline (S group) or phenylephrine to restore vascular tone (P group) (n = 26 each). Both groups received an infusion of 8 mL/kg 6% HES solution after induction of general anaesthesia. We compared ΔPVHb at the end of fluid infusion (15 minutes) and 15 minutes later (30 minutes) between the two groups. We assessed changes in ESL structure by measuring plasma concentrations of hyaluronate and syndecan-1. P < .05 was considered statistically significant. RESULTS: Mean arterial blood pressure was lower in the S group approximately by 30-40% compared to the P group (P < .001). ΔPVHb was larger in the S group compared to the P group at 15 minutes (24.9 [5.2] % vs 19.0 [5.2] %; P < .001) and 30 minutes (26.5 [5.9] % vs 16.9 [6.6] %; P < .001). There were no clinically significant differences in plasma concentrations of hyaluronate and syndecan-1 with time and between the groups. CONCLUSIONS: Increased volume expansion of circulating plasma following HES infusion in anaesthesia-induced hypotension compared to when blood pressure is restored by phenylephrine may result from an attenuation of transcapillary fluid filtration, rather than ESL shedding. UMIN Clinical Trial Registration Number: UMIN000017394 (http://www.umin.ac.jp/ctr/index.htm).

A randomized, controlled, double-blind crossover study on the effects of isoeffective and isovolumetric intravenous crystalloid and gelatin on blood volume, and renal and cardiac hemodynamics.

BACKGROUND & AIMS: Blood volume expanding properties of colloids are superior to crystalloids. In addition to oncotic/osmotic properties, the electrolyte composition of infusions may have important effects on visceral perfusion, with infusions containing supraphysiological chloride causing hyperchloremic acidosis and decreased renal blood flow. In this non-inferiority study, a validated healthy human subject model was used to compare effects of colloid (4% succinylated gelatin) and crystalloid fluid regimens on blood volume, renal function, and cardiac output. METHODS: Healthy male participants were given infusions over 60 min > 7 days apart in a randomized, crossover manner. Reference arm (A): 1.5 L of Sterofundin ISO, isoeffective arm (B): 0.5 L of 4% Gelaspan®, isovolumetric arm (C): 0.5 L of 4% Gelaspan® and 1 L of Sterofundin ISO (all B. Braun, Melsungen, Germany). Participants were studied over 240 min. Changes in blood volume were calculated from changes in weight and hematocrit. Renal volume, renal artery blood flow (RABF), renal cortex perfusion and diffusion, and cardiac index were measured with magnetic resonance imaging. RESULTS: Ten of 12 males [mean (SE) age 23.9 (0.8) years] recruited, completed the study. Increase in body weight and extracellular fluid volume were significantly less after infusion B than infusions A and C, but changes in blood volume did not significantly differ between infusions. All infusions increased renal volume, with no significant differences between infusions. There was no significant difference in RABF across the infusion time course or between infusion types. Renal cortex perfusion decreased during the infusion (mean 18% decrease from baseline), with no significant difference between infusions. There was a trend for increased renal cortex diffusion (4.2% increase from baseline) for the crystalloid infusion. All infusions led to significant increases in cardiac index. CONCLUSIONS: A smaller volume of colloid (4% succinylated gelatin) was as effective as a larger volume of crystalloid at expanding blood volume, increasing cardiac output and changing renal function. Significantly less interstitial space expansion occurred with the colloid. TRIAL REGISTRATION: The protocol was registered with the European Union Drug Regulating Authorities Clinical Trials Database (https://eudract.ema.europa.eu) (EudraCT No. 2013-003260-32).

Paracentesis-Induced Circulatory Dysfunction With Modest-Volume Paracentesis Is Partly Ameliorated by Albumin Infusion in Acute-on-Chronic Liver Failure.

BACKGROUND AND AIMS: Paracentesis-induced circulatory dysfunction (PICD) is a serious complication of large-volume (>5 L) paracentesis in cirrhosis and is reduced with albumin infusion. There is a lack of data on PICD in acute-on-chronic liver failure (ACLF). Because ACLF patients have greater hemodynamic derangements than patients with decompensated cirrhosis, we investigated whether PICD could develop with modest-volume paracentesis (MVP) and the role of albumin infusion. APPROACH AND RESULTS: A total of 80 ACLF patients undergoing <5 L paracentesis were randomized to receive albumin (8 g/dL of ascitic fluid; n = 40) or no albumin (n = 40) and serially followed to detect PICD. Baseline characteristics were comparable between groups, including volume of ascitic tap (4.16 ± 0.23 versus 4.14 ± 0.27 L; P = 0.72) and plasma renin activity (PRA; 20.5 ± 7.03 versus 23.2 ± 8.24 ng/mL/hour; P = 0.12). PICD was more frequent in the no-albumin group than the albumin group (70% versus 30%; P = 0.001), with higher incidence of hepatic encephalopathy (50% versus 27.5%; P = 0.04), hyponatremia (67.5% versus 22.5%; P < 0.001), acute kidney injury (62.5% versus 30%; P = 0.001), and in-house mortality (62.5% versus 27.5%; P = 0.003). PRA of 25.15 ng/mL at day 3 had sensitivity and specificity of 71% and 68%, respectively, for development of PICD at day 6. Albumin infusion decreased the incidence of PICD at day 6 (odds ratio, 0.068; 95% confidence interval, 0.011-0.43; P = 0.005). CONCLUSIONS: PICD is common and develops even with MVP in ACLF patients. Albumin infusion decreases the incidence of PICD and mortality in patients with ACLF. Clinical trial identifier: NCT02467348.

Effect of goal-directed crystalloid- versus colloid-based fluid strategy on tissue oxygen tension: a randomised controlled trial.

BACKGROUND: Sufficient tissue oxygen tension may reduce the risk of postoperative wound infections. Supplemental administration of crystalloids increases subcutaneous oxygen tension (Psqo2). Colloids remain longer in the intravascular system and might therefore increase Psqo2 even more than crystalloids. Therefore, we tested the hypothesis that goal-directed colloid administration increases the perioperative Psqo2 more compared with crystalloid administration. METHODS: We randomly assigned 80 patients undergoing elective open abdominal surgery to receive fluid boluses of hydroxyethyl starch (HES) or lactated Ringer's (LR) solution guided by oesophageal Doppler. Intraoperative Psqo2 was measured in the upper arm. After operation, we measured the Psqo2 in the upper arm and in the surgical wound. RESULTS: Forty patients were enrolled in each group. Patients in the colloid group received HES solution 750 ml (500; 1000) and LR solution 1500 ml (1000; 2000). Patients in the crystalloid group received LR solution 2825 ml (2000; 3960). The goal-directed administration of colloids did not improve intraoperative Psqo2 in the arm compared with crystalloid administration (11.4 kPa [9.0; 16.6] vs 11.2 kPa [8.6; 15.1], respectively; P=0.58). Postoperative arm Psqo2 was 8.1 kPa (6.5; 9.6) in the colloid group and 7.3 kPa (5.7; 9.1) in the crystalloid group (P=0.11). Postoperative surgical wound Psqo2 was 10.7 kPa (8.6; 13.4) in the colloid group and 10.1 kPa (8.1; 12.7) in the crystalloid group (P=0.68). CONCLUSIONS: Goal-directed colloid administration did not increase Psqo2 compared with goal-directed crystalloid administration in patients undergoing open abdominal surgery. CLINICAL TRIAL REGISTRATION: NCT00517127.

The influence of different resuscitation solution on lactic acid accumulation after hemorrhagic shock: a network meta-analysis.

OBJECTIVE: To compare the effect of various fluid resuscitation procedures after hemorrhagic shock on the lactic acid accumulation by network meta-analysis. MATERIALS AND METHODS: A number of articles were obtained by searching the databases. Randomized control trials (RCT) were selected by two literature quality assessors; the extracted experimental data were then summarized to compare and analyze the effect of various kinds of infusion procedures at different time points on the concentration of lactic acid in the internal environment of rat models. RESULTS: 9 articles containing 25 independent reports were enrolled. Results revealed that the accumulation of lactic acid generated in the resuscitation using hydroxyethyl starch solution or gelofusine was significantly different from the one using Ringer solution, hypertonic saline or normal salt solution (p<0.05). Compared to the colloidal, the aqueous solution of pyruvate showed a slightly weaker effect in reducing the accumulation of lactic acid. The accumulation of lactic acid is severely affected by hypertonic saline, Ringer lactate solution, and balanced salt solution, i.e., the concentration of lactic acid is increasing with an augment of concentration or prolongation of treatment time. CONCLUSIONS: In terms of the management of lactic acid accumulation after hemorrhagic shock, the effect of colloidal solution was remarkably better than a crystalloid solution, and hypertonic saline and normal salt solution were not recommended as preferable drugs in the treatment of hemorrhagic shock.

[Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial]. / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico.

BACKGROUND AND OBJECTIVES: Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. METHODS: Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. RESULTS: In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p>0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p<0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p<0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p>0.05). CONCLUSION: Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Rotational thromboelastometry assessment of ballanced crystalloid, hydroxyethyl starch and gelatin effects on coagulation: a randomized trial / Tromboelastometria rotacional na avaliação dos efeitos de cristaloides balanceados, hidroxietilamido e gelatina na coagulação: estudo randômico

Abstract Background and objectives Modern crystalloid and colloid solutions are balanced solutions which are increasingly used in perioperative period. However, studies investigating their negative effect on whole blood coagulation are missing, and vivid debate is going on about which solution has the minimal coagulopathy effect. The aim of our study was to assess the effect of modern fluid solutions on whole blood coagulation using rotational thromboelastometry. Methods Blood samples were obtained from 30 patients during knee arthroscopy before and after administration of 500 mL of crystalloid, Hydroxyethyl Starch and gelatin according to the randomization. Rotational thromboelastometry (Extem, Intem and Fibtem tests) was used to assess negative effect of fluid solutions on whole blood coagulation. Results In Extem test, the initiation phase of fibrin clot formation represented by CT parameter was not influenced by any fluid solution (p > 0.05). The speed of clot formation represented by CFT and α angle was impaired by Hydroxyethyl Starch and gelatin but not by crystalloids (p < 0.05). The strength of formatted coagulum represented by MCF parameter was impaired both in Extem and Fibtem test by HES and in Fibtem also by crystalloids (p < 0.05). Intem test was not negatively influenced by any crystalloid or colloid solution in any parameter (p > 0.05). Conclusion Extem test appears to be sensitive to coagulopathy effect of modern colloids and crystalloids. Hydroxyethyl starch has the most obvious negative effect on clot formation followed by gelatin and finally by crystalloids. Intem test seems to be insensitive to adverse effect of modern colloids and crystalloids.

Resumo Justificativa e objetivos Os cristaloides e coloides modernos são soluções balanceadas e cada vez mais utilizadas no período perioperatório. No entanto, não há estudos que avaliem seu efeito negativo na coagulação do sangue total e o intenso debate sobre a solução que cause um efeito mínimo na coagulopatia permanece. O objetivo de nosso estudo foi avaliar o efeito das soluções líquidas modernas na coagulação do sangue total com o uso da tromboelastometria rotacional. Métodos De acordo com a randomização, amostras de sangue foram colhidas de 30 pacientes durante a artroscopia de joelho, antes e após a administração de 500 mL de cristaloides, hidroxietilamido e gelatina. A tromboelastometria rotacional (testes Extem, Intem e Fibtem) foi utilizada para avaliar o efeito negativo das soluções líquidas na coagulação do sangue total. Resultados No teste Extem, a fase de iniciação da formação de coágulos de fibrina representada pelo parâmetro CT não foi influenciada por qualquer solução líquida (p > 0,05). A velocidade da formação de coágulos representada pelo CFT e pelo ângulo α foi prejudicada pelo hidroxietilamido e pela gelatina, mas não pelos cristaloides (p < 0,05). A força do coágulo formatado representado pelo parâmetro MCF foi prejudicada tanto no teste Extem quanto no teste Fibtem pelo HES e no teste Fibtem também pelos cristaloides (p < 0,05). O teste Intem não foi influenciado negativamente por nenhuma solução cristaloide ou coloide em nenhum parâmetro (p > 0,05). Conclusão O teste Extem parece ser sensível ao efeito de coagulopatia dos coloides e cristaloides modernos. O hidroxietilamido apresentou o efeito negativo mais óbvio na formação do coágulo, seguido pela gelatina e finalmente pelos cristaloides. O teste Intem parece ser insensível ao efeito adverso dos coloides e cristaloides modernos.