Fluid Bolus Infusion Research Articles

Impact of the fluid challenge infusion rate on cardiac stroke volume during major spinal neurosurgery: a prospective single center randomized interventional trial

BackgroundFluid therapy, including the choice of a crystalloid or colloid infusion, the execution time of a volume bolus, and the expected volume need of a patient during surgery, varies greatly in clinical practice. Different goal directed fluid protocols have been developed, where fluid boluses guided by dynamic preload parameters are administered within a specific period.ObjectiveTo study the efficacy of two fluid bolus infusion rates measured by the response of hemodynamic parameters.DesignMonocentric randomized controlled interventional trial.SettingUniversity hospital.PatientsForty patients undergoing elective major spinal neurosurgery in prone position were enrolled, thirty-one were finally analyzed.InterventionsPatients were randomly assigned to receive 250 ml crystalloid and colloid boluses within 5 min (group 1) or 20 min (group 2) when pulse pressure variation (PPV) exceeded 14%.Main outcome measuresChanges in stroke volume (SV), mean arterial pressure (MAP), and catecholamine administration.ResultsGroup 1 showed a greater increase in SV (P = 0.031), and MAP (P = 0.014), while group 2 still had higher PPV (P = 0.005), and more often required higher dosages of noradrenalin after fluid administration (P = 0.033). In group 1, fluid boluses improved CI (P < 0.01), SV (P < 0.01), and MAP (P < 0.01), irrespective of whether crystalloids or colloids were used. In group 2, CI and SV did not change, while MAP was slightly increased (P = 0.011) only after colloid infusion.ConclusionsA fluid bolus within 5 min is more effective than those administered within 20 min and should therefore be the primary treatment option. Furthermore, bolus infusions administered within 20 min may result in volume overload without achieving relevant hemodynamic improvements.Trial registrationGerman Clinical Trials Register: DRKS00022917.

Feasibility of Dialysate Bolus-Based Absolute Blood Volume Estimation in Maintenance Hemodialysis Patients.

BackgroundAbsolute blood volume (ABV) is a critical component of fluid status, which may inform target weight prescriptions and hemodynamic vulnerability of dialysis patients. Here, we utilized the changes in relative blood volume (RBV), monitored by ultrasound (BVM) upon intradialytic 240 mL dialysate fluid bolus-infusion 1 h after hemodialysis start, to calculate the session-specific ABV. With the main goal of assessing clinical feasibility, our sub-aims were to (i) standardize the BVM-data read-out; (ii) determine optimal time-points for ABV-calculation, “before-” and “after-bolus”; (iii) assess ABV-variation.MethodsWe used high-level programming language and basic descriptive statistics in a retrospective study of routinely measured BVM-data from 274 hemodialysis sessions in 98 patients.ResultsRegarding (i) and (ii), we automatized the processing of RBV-data, and determined an algorithm to select the adequate RBV-data points for ABV-calculations. Regarding (iii), we found in 144 BVM-curves from 75 patients, that the average ABV ± standard deviation was 5.2 ± 1.5 L and that among those 51 patients who still had ≥2 valid estimates, the average intra-patient standard deviation in ABV was 0.8 L. Twenty-seven of these patients had an average intra-patient standard deviation in ABV <0.5 L.ConclusionsWe demonstrate feasibility of ABV-calculation by an automated algorithm after dialysate bolus-administration, based on the BVM-curve. Based on our results from this simple “abridged” calculation approach with routine clinical measurements, we encourage the use of multi-compartment modeling and comparison with reference methods of ABV-determination. Hopes are high that clinicians will be able to use ABV to inform target weight prescription, improving hemodynamic stability.

Complex effects of continuous vasopressor infusion on fluid responsiveness during liver resection

Fluid responsiveness is an important factor to consider for fluid volume loading during major surgery. The effect of continuous vasopressor infusion on fluid responsiveness during prolonged major surgery is a concern. We hypothesised that continuous vasopressor infusion during major surgery might not exert significant effects on changes in stroke volume variation (SVV) following fluid bolus infusion, and thereby on fluid responsiveness. Randomised controlled trial. University hospital from April 2014 to August 2016. Patients undergoing liver resection who were randomised to receive continuous intravenous infusion of phenylephrine (P group), norepinephrine (N group), or no vasopressor (C group) (n=17/group). Exclusion criteria were cardiac arrhythmia and severe cardiac, pulmonary or renal dysfunction. Patients received 4 ml kg fluid boluses of 6% hydroxyethyl starch solution when SVV was at least 12%. Vasopressors were administered continuously to maintain the systemic vascular resistance index at more than 1900 dyn s cm m. Cardiac index and SVV were measured using the FloTrac/Vigileo system (Version 4.00). The number of fluid boluses with fluid responsiveness (i.e. >15% increase in cardiac index) was compared between groups using multilevel logistic regression analysis. Numbers of fluid responsive boluses in the C, P and N groups were 12 (14%), 22 (34%) and 19 (27%), respectively. Odds ratios on fluid responsiveness for phenylephrine and norepinephrine compared with the control were 3.65 (97.5% confidence interval, 1.15 to 11.6; P = 0.012) and 2.56 (97.5% confidence interval, 0.82 to 8.00; P = 0.064), respectively. Decreases in SVV after fluid bolus infusion for the P and N groups were comparable with the C group (P = 0.23 and 0.53, respectively). Continuous administration of phenylephrine increased fluid responsiveness during liver resection, suggesting complex effects of continuous vasopressor infusion involving changes in cardiac preload and afterload. UMIN000011024.

Abstract P-033: ACCURACY OF PASSIVE LEG RAISING TEST IN PREDICTING OF FLUID RESPONSIVENESS IN CHILDREN ON ULTRASONIC CARDIAC OUTPUT MONITORING (USCOM®)

Aims & Objectives: To determine the accuracy of PLRT in predicting fluid responsiveness in children with Ultrasonic Cardiac Output Monitoring (USCOM®) monitoring. Methods Methods: This study is a prospective cohort study in pediatric intensive care unit (PICU) at Academic referral center in Thailand, performed from November 1st 2016 to April 30th 2017. Infants or children with clinical conditions of volume deficit without hypotension were recruited to the study. USCOM® was used as a non-invasive hemodynamic monitoring. Cardiac index (CI) and other basic hemodynamic parameters were recorded at baseline, after PLRT, and after infusion of fluid bolus. The patients with increased in CI% more than 10% after fluid bolus infusion, were considered as fluid responsiveness. Results A total of fifty patients were enrolled, thirty-one patients were excluded mostly due to in-cooperation. Nineteen patients can follow the protocol until the end. Their mean age was 85.8 ± 69.5 months. The results showed that increasing in CI% after PLRT more than 10%, could potentially predict fluid responsiveness, with the sensitivity, specificity, positive predictive value and negative predictive value of 44%, 90%, 80% and 64.3%, respectively. The percentage change of parameters (delta CI%, delta SVI%, delta SVRI % and delta FTc%) after PLRT and after infusion fluid bolus has the R-correlation of 0.502, 0.608, -0.766 and 0.599 (P-value < 0.05). Conclusions PLRT measured by USCOM can predict fluid responsiveness in children with good specificity. Although, positive PLRT might be used as a confirmatory test but not to use as a screening tool to predict volume responsiveness.

Is There a Role for Balanced Solutions in Septic Patients?

The use of fluid bolus infusion is the cornerstone for hemodynamic resuscitation of critically ill patients. Recently, the clinical use of colloids has lost strength with the publication of several trials suggesting no benefit, and possible harm of its use.On the other hand, the so-called balanced solutions, with low chloride concentrations, have emerged as an alternative with potential physiological benefits over traditional saline solution. Normal saline carries a high amount of chloride which has been associated with an increased incidence of metabolic acidosis, renal vasoconstriction, and reduced urine output. Recent observational studies associated the use of saline with acute kidney injury, which was not observed in a single prospective randomized controlled trial.The present review summarizes available literature regarding the potential clinical and laboratorial benefits of balanced solutions in septic patients.

Relationship between Stroke Volume Variation and Stroke Volume during Major Abdominal Surgery Using Arterial Pulse Contour Analysis

Objective: Changes in stroke volume after fluid bolus infusion (i.e., fluid responsiveness) during major abdominal surgery is affected by painful stimuli, anesthetics and inconsistent increases in cardiac preload following each round of fluid infusion. This study aimed to assess the relationship between stroke volume variation (SVV) and stroke volume during major abdominal surgery using arterial pulse contour analysis by removing data of stroke volume affected by these factors. Methods: Eighty-three patients who underwent major abdominal surgery received 8 ml/kg boluses of either Ringer’s acetate or 6% hydroxyethyl starch 70/0.5 solution over the course of 30 minutes. Stroke volume index (SVI) and SVV were obtained using the FloTracTM/VigileoTM system (Version 3.02). Patients were classified according to values of absolute changes of SVV (ΔSVV, %) and relative changes of SVI (ΔSVI, %) following fluid bolus infusion. For each patient, ΔSVI was linearly regressed against SVV at different time points during the 60 minute period after initiation of bolus infusion. The relationship between SVV and ΔSVI was examined using the angle (radian) of the slope of ΔSVI against SVV. Results: Following fluid bolus infusion, SVI increased in 43% of patients due to an increase in cardiac preload (i.e., SVV decrease), and 33% of patients showed false SVI responses (ΔSVV 0). Angle values for SVV-ΔSVI in 50 patients were consistent in the SVV range of 9%-20% (i.e., 1.2); a 4% decrease in SVV resulted in a 10% increase in SVI. Conclusions: One-third of patients undergoing major abdominal surgery showed false responses for SVI following fluid bolus infusion. After excluding false responses for SVI, the relationship between SVV and ΔSVI during major abdominal surgery was almost linear in the SVV range of 9%-20%, suggesting that SVV changes following fluid bolus infusion significantly contribute to fluid responsiveness.

Fluid Responsiveness and Brain Tissue Oxygen Augmentation After Subarachnoid Hemorrhage

The objective of this study was to investigate the relationship between cardiac index (CI) response to a fluid challenge and changes in brain tissue oxygen pressure (PbtO(2)) in patients with subarachnoid hemorrhage (SAH). Prospective observational study was conducted in a neurological intensive care unit of a university hospital. Fifty-seven fluid challenges were administered to ten consecutive comatose SAH patients that underwent multimodality monitoring of CI, intracranial pressure (ICP), and PbtO(2), according to a standardized fluid management protocol. The relationship between CI and PbtO(2) was analyzed with logistic regression utilizing generalized estimating equations. Of the 57 fluid boluses analyzed, 27 (47 %) resulted in a ≥ 10 % increase in CI. Median absolute (+5.8 vs. +1.3 mmHg) and percent (20.7 vs. 3.5 %) changes in PbtO(2) were greater in CI responders than in non-responders within 30 min after the end of the fluid bolus infusion. In a multivariable model, a CI response was independently associated with PbtO(2) response (adjusted odds ratio 21.5, 95 % CI 1.4-324, P = 0.03) after adjusting for mean arterial pressure change and end-tidal CO(2). Stroke volume variation showed a good ability to predict CI and PbtO(2) response with areas under the ROC curve of 0.86 and 0.81 with the best cut-off values of 9 % for both responses. Bolus fluid resuscitation resulting in augmentation of CI can improve cerebral oxygenation after SAH.

Letters to the Editor

Letters to the Editor

Time-Varying Elastance Concept Applied to the Relation of Carotid Arterial Flow Velocity and Ventricular Area

In this study, the relationship V(f)AR, which was obtained from carotid blood-flow velocity (V(f)) and the cross-sectional area (A) of the left ventricle, was used to assess changes in left ventricular (LV) systolic performance as indicated by the LV pressure-volume relationship (PVR) and end-systolic LV elastance (E(es)). The relationship of maximum systolic V(f) as a surrogate for LV pressure and end-systolic LV area as a surrogate for end-systolic LV volume may allow for the estimation of LV elastance and ejection properties. In 25 pigs, internal carotid V(f) was recorded by using continuous-wave Doppler mode. Echocardiographic measurements of A were continuously performed with an automated border detection system and combined with data for V(f) to display V(f)AR as a series of loop diagrams. These were shifted during acute preload reduction, and an index E'(es) was calculated by applying the time varying elastance concept to end-systolic V(f)AR. Simultaneously, E(es) was acquired by conductance catheter and micromanometer techniques. Comparisons of E'(es) and E(es) were made at various contractility levels obtained by the administration of dobutamine, 5 microg/kg/min, and esmolol, 40 to 60 mg, and at various cardiac load levels, obtained by a fluid bolus infusion or administration of a vasoconstrictor. Highly linear elastance curves (r >or= 0.85, p < 0.0001) were derived from both end-systolic V(f)AR and PVR. Correlation of E'(es) and E(es) revealed an almost linear function: E'(es) = 0.052 + 0.11 E(es) (r = 0.98, p < 0.0001). Administration of dobutamine increased E(es) from 5.8 +/- 3.04 mmHg/mL to 10.1 +/- 4.19 mmHg/mL (p < 0.05), and E('es) from 0.68 +/- 0.288 cm(2)/min/mL to 1.24 +/- 0.458 cm(2)/min/mL (p < 0.05). After administration of esmolol, E(es) and E'(es) both dropped significantly by 3.7 +/- 2.4 mmHg/mL and 0.44 +/- 0.15 cm(2)/min/mL, respectively. No load dependency of E'(es) was seen. Bland-Altman analysis revealed that the change in E'(es), which is required to predict a significant change in E(es), should exceed +16.9% or -13.1% of the preceding value. Application of the time-varying elastance concept on the relation of V(f) and LV area allows for the determination of an index E'(es) that may be used to estimate E(es).

Base administration or fluid bolus for preventing morbidity and mortality in preterm infants with metabolic acidosis.

Metabolic acidosis in the early newborn period is associated with adverse outcomes in preterm infants. The most commonly used strategies to correct metabolic acidosis are intravascular infusion of base, for example sodium bicarbonate, and intravascular infusion of a fluid bolus, usually a crystalloid or colloid solution. To evaluate the available evidence from randomised controlled trials that either infusion of base, or of a fluid bolus, reduces mortality and adverse neurodevelopmental outcomes in preterm infants with metabolic acidosis. We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005), MEDLINE (1966 - January 2005), EMBASE (1980 - January 2005), CINAHL (1982 - January 2005). Randomised or quasi-randomised controlled trials that evaluated the following treatments for preterm infants with metabolic acidosis:1. Infusion of base versus no treatment.2. Infusion of fluid bolus versus no treatment.3. Infusion of base versus fluid bolus. We extracted the data using the standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two authors, and synthesis of data using relative risk and risk difference. We found two small randomised controlled trails that fulfilled the eligibility criteria (Corbet 1977; Dixon 1999). Corbet 1977 compared treating infants with sodium bicarbonate infusion (N = 30) versus no treatment (N = 32) and did not find evidence of an effect on mortality [Relative risk 1.39 (95% confidence interval 0.72 to 2.67), risk difference 0.12 (95% confidence interval -0.12 to 0.36)], or in the incidence of intra/peri-ventricular haemorrhage [Relative risk 1.24 (95% confidence interval 0.47 to 3.28), risk difference 0.05 (95% confidence interval -0.16 to 0.25)]. Dixon 1999 compared treatment with sodium bicarbonate (N = 16) versus fluid bolus (N = 20). The primary outcome assessed was arterial blood pH/base excess two hours after the intervention. Other clinical outcomes were not reported. Neither trial assessed longer term neurodevelopmental outcomes. There is insufficient evidence from randomised controlled trials to determine whether infusion of base or fluid bolus reduces morbidity and mortality in preterm infants with metabolic acidosis. Further large randomised trials are needed.

A new method for rapid fluid bolus infusion into a peripheral vein

Objective. To compare the flow rates achieved by a new short-tubed infusion device with those obtained with a conventional apparatus, using gravity, manual pressure, andMethods. Ten paramedic volunteers were recruited for this prospective, randomized, controlled laboratory study. For the short-tubing setup, a new device, the port, was used to adapt standard 18-cm extension tubing directly to an IV bag [short tubing/ port (STP) setup]. For the conventional (CON) setup, 280-cm tubing was used. Both study setups were tested on each of the volunteers with flow from a standard 250-mL bag of normal saline subjected to three types of driving force: 1) gravity alone, 2) pressure supplied by two hands squeezing the IV bag, and 3) a pneumatic pressure bag continuously inflated to 300 mm Hg. The mean flow rates for each driving force were compared between the two setups. Results. Using gravity flow, no significant difference was noted between the STP setup and the CON setup (0.40 vs 0.45 mL/sec, respectively, p > 0.4). However, when flow was augmented by pressure supplied by two hands squeezing the bag, mean flow was greater for the STP setup than for the CON setup (4.5 vs 2.7 mL/sec, respectively, p < 0.001). When flow was augmented by a pneumatic bag at 300 mm Hg, mean flow was again greater for the STP setup (5.6 mL/sec) than for the CON setup (3.3 mL/sec, p < 0.001).Conclusion. Flow of crystalloid under pressure into a peripheral vein is markedly increased with the new STP setup as compared with the CON setup. Incorporation of this new setup in prehospital care would allow EMS personnel to infuse fluid more rapidly and conveniently during transport.