Comparison of stroke volume and fluid responsiveness measurements in commonly used technologies for goal-directed therapy

Predicting fluid responsiveness using esophagus Doppler monitoring and pulse oximetry derived pleth variability index; retrospective analysis of a hemodynamic study

BACKGROUND

Fluid therapy during major surgery can be managed by providing repeated bolus infusions until stroke volume no longer increases by ≥ 10%. However, the final bolus in an optimization round increases stroke volume by < 10% and is not necessary. We studied how different cut-off values for the hemodynamic indications given by esophagus Doppler monitoring, as well as augmentation by pulse oximetry, are associated with a higher or smaller chance that stroke volume increases by ≥ 10% (fluid responsiveness) before fluid is infused.

METHODS

An esophagus Doppler and a pulse oximeter that displayed the pleth variability index were used to monitor the effects of a bolus infusion in 108 patients undergoing goal-directed fluid therapy during major open abdominal surgery.

RESULTS

The analyzed data set comprised 266 bolus infusions. The overall incidence of fluid responsiveness was 44%, but this varied greatly depending on pre-infusion hemodynamics. The likelihood of being fluid-responsive was 30%-38% in the presence of stroke volume > 80 mL, corrected flow time > 360 ms, or pleth variability index < 10%. The likelihood was 21% if stroke volume had decreased by <8% since the previous optimization, which decreased to 0% if combined with stroke volume > 100 mL. By contrast, the likelihood of fluid responsiveness increased to 50%-55% when stroke volume ≤ 50 mL, corrected flow time ≤ 360 ms, or pleth variability index ≥ 10. A decrease in stroke volume by > 8% since the previous optimization was followed by a 58% likelihood of fluid responsiveness that, in combination with any of the other hemodynamic variables, increased to 66%-76%.

CONCLUSIONS

Single or combined hemodynamic variables provided by esophagus Doppler monitoring and pulse oximetry derived pleth variability index could help clinicians avoid unnecessary fluid bolus infusions.

Ward based goal directed fluid therapy (GDFT) in acute pancreatitis (GAP) trial: A feasibility randomised controlled trial

BACKGROUND

Goal-directed fluid therapy (GDFT) reduces complications in patients undergoing major general surgery. There are no reports of cardiac output evaluation being used to optimise the fluid administration for patients with acute pancreatitis (AP) in a general surgery ward.

METHOD

50 patients with AP were randomised to either ward-based GDFT (n = 25) with intravenous (IV) fluids administered based on stroke volume optimisation protocol or standard care (SC) (n = 25), but with blinded cardiac output evaluation, for 48-h following hospital admission. Primary outcome was feasibility.

RESULTS

50 of 116 eligible patients (43.1%) were recruited over 20 months demonstrating feasibility. 36 (72%) completed the 48-h of GDFT; 10 (20%) discharged within 48-h and 4 withdrawals (3 GDFT, 1 SC). Baseline characteristics were similar with only 3 participants having severe disease (6%, 1 GDFT, 2 SC). Similar volumes of IV fluids were administered in both groups (GDFT 5465 (1839) ml, SC 5211 (1745) ml). GDFT group had a lower heart rate, blood pressure and respiratory rate and improved oxygen saturations. GDFT was not associated with any harms. There was no evidence of difference in complications of AP (GDFT 24%, SC 32%) or in the duration of stay in intensive care (GDFT 0 (0), SC 0.7 [(Van DIjk et al., 2017) 33 days). Length of hospital stay was 5 (2.9) days in GDFT and 6.3 (7.6) in SC groups.

CONCLUSION

Ward-based GDFT is feasible and shows a signal of possible efficacy in AP in this early-stage study. A larger multi-site RCT is required to confirm clinical and cost effectiveness.

Myocardial edema in paroxysmal permeability disorders: The paradigm of Clarkson's disease

PURPOSE

Paroxysmal Permeability Disorders (PPDs) comprise a variety of diseases characterized by recurrent and transitory increase of endothelial permeability. Idiopathic Systemic Capillary Leak Syndrome (ISCLS) is a rare PPD that leads to an abrupt massive shift of fluids and proteins from the intravascular to the interstitial compartment. In some cases, tissue edema may involve the myocardium, but its role in the development of shock has not been elucidated so far.

MATERIALS AND METHODS

Assessment of cardiac involvement during ten life-threatening ISCLS episodes admitted to ICU.

RESULTS

Transthoracic echocardiographic examination was performed in eight episodes, whereas a poor acoustic window prevented cardiac ultrasound assessment in two episodes. Myocardial edema was detected by echocardiography in eight episodes and marked pericardial effusion in one-episode. Cardiac magnetic resonance showed diffuse myocardial edema in another episode. In one case, myocardial edema caused fulminant left ventricular dysfunction, which required extracorporeal life support. The mean septum thickness was higher during the shock phase compared to the recovery phase [15.5 mm (13.1-21 mm) vs. 9.9 mm (9-11.3 mm), p = .0003]. Myocardial edema resolved within 72 h.

CONCLUSIONS

During early phases of ISCLS, myocardial edema commonly occurs and can induce transient myocardial dysfunction, potentially contributing to the pathogenesis of shock.

The plethysmographic variability index does not predict fluid responsiveness estimated by esophageal Doppler during kidney transplantation: A controlled study

Research is ongoing to find a noninvasive method of monitoring, which can predict fluid responsiveness in patients undergoing kidney transplantation.To compare the responses to fluid challenges with the Pleth Variability Index, a noninvasive dynamic index derived from plethysmographic variability (Radical 7 pulse oximeter; Masimo Corporation, Irvine, CA), and the esophageal Doppler, the criterion standard.Observational study.University hospital; study from May 2011 and May 2012.Forty-eight patients with end-renal function were included and 44 analyzed. Patients with cardiac failure were not eligible.Fluid challenges were administered during maintenance of general anesthesia but before skin incision and repeated if the patient was deemed to be a "responder" (increase in stroke volume ≥10%).The primary endpoint was to assess if the Pleth Variability Index is an accurate predictor of fluid responsiveness.Among 76 fluid challenges, 38 were considered as positive (increase in stroke volume measured by Doppler ≥10%). Pleth Variability Index was similar at baseline between responders and nonresponder patients. Fluid challenges were associated with a significant decrease in Pleth Variability Index in overall cases (12 [8-14] vs 10 [6-17], P = .050), but it was not able to discriminate between responders (12 [8-15] vs 10 [5-15], P = .650) and nonresponders (11 [6-16] vs 8 [5-14], P = .047). The area under the Receiver Operating Characteristic curve for Pleth Variability Index was 0.49 (0.36-0.62).Pleth Variability Index is not an accurate predictor of fluid responsiveness during kidney transplantation.

The ability of left ventricular end-diastolic volume variations measured by TEE to monitor fluid responsiveness in high-risk surgical patients during craniotomy: a prospective cohort study

BACKGROUND

This study was aimed to evaluate the ability of left ventricular end-diastolic volume variations (LVEDVV) measured by transesophageal echocardiography (TEE) compared with stroke volume variation (SVV) obtained by the FloTrac/Vigileo monitor to predict fluid responsiveness, in patients undergoing craniotomy with goal direct therapy.

METHODS

We used SVV obtained by the FloTrac/Vigileo monitor to manage intraoperative hypotension in adult patients undergoing craniotomy (ASA III - IV) after obtaining IRB approval and informed consent. The LVEDVV were measured by TEE through the changes of left ventricular short diameter of axle simultaneously. When cardiac index (CI) ≤ 2.5 and SVV ≥ 15%, comparisons were made between the two devices before and after volume expansion.

RESULTS

We enrolled twenty-six patients referred for craniotomy in this study and 145 pairs of data were obtained. Mean Vigileo-SVV and TEE-LVEDVV were 17.8 ± 2.78% and 22.1 ± 7.25% before volume expansion respectively, and were 10.95 ± 2.8% and 13.58 ± 3.78% after volume expansion respectively (P < 0.001). The relationship between Vigileo-SVV and TEE-LVEDVV was significant (r2 = 0.55; p < 0.001). Agreement between Vigileo-SVV and TEE-LVEDVV was 3.3% ± 3.9% (mean bias ± SD, Bland-Altman).

CONCLUSIONS

For fluid responsiveness of patients during craniotomy in ASA III-IV, LVEDVV measured by left ventricular short diameter of axle using M type echocaidiographic measurement seems an acceptable monitoring indicator. This accessible method has promising clinical applications in situations where volume and cardiac function monitoring is of great importance during surgery.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-TRC-13003583 , August 20, 2013.

The Effect of a Surgery-Specific Cardiac Output–Guided Haemodynamic Algorithm on Outcomes in Patients Undergoing Pancreaticoduodenectomy in a High-Volume Centre: A Retrospective Comparative Study

In this retrospective observational study performed in a high-volume hepatobiliary–pancreatic unit, we evaluated the effect of a surgery-specific goal-directed therapy (GDT) physiologic algorithm on complications and length of hospital stay. We compared patients who underwent pancreaticoduodenectomy with either a standardised Enhanced Recovery After Surgery program (usual care group), or a standardised Enhanced Recovery After Surgery program in combination with a surgery-specific cardiac output–guided algorithm (GDT group). We included 145 consecutive patients: 47 in the GDT group and 98 in the usual care group. Multivariable associations between GDT and lengths of stay and complications were investigated using negative binomial regression. Postoperative complications were common and occurred at similar frequencies amongst the GDT and usual care groups: 64% versus 68% respectively, P=0.71; odds ratio 0.82; (95% confidence interval 0.39–1.70). There were fewer cardiorespiratory complications in the GDT group. Median (interquartile range) length of hospital stay was ten days (8.0–14.0) in the GDT group compared to 13 days (8.8–21.3) in the usual care group, P=0.01. Median (interquartile range) total intraoperative fluid was 3,000 ml (2,050–4,175) in the GDT group compared to 4,500 ml (3,275–5,325) in the usual care group, P <0.0001; but by day one, the median (interquartile range) fluid balance was similar (1,198 ml [700–1,729] in the GDT group versus 977 ml [419–2,044] in the usual care group, P=0.96). Use of vasoactive medications was higher in the GDT group. In our patients undergoing pancreaticoduodenectomy, GDT was associated with restrictive intraoperative fluid intervention, fewer cardiorespiratory complications and a shorter hospital length of stay compared to usual care. However, we could not exclude an influence of surgical caseload, which we have previously found to be an important variable. We also could not relate the increased hospital length of stay to cardiorespiratory complications in individual patients. Therefore, these observational retrospective findings would require confirmation in a prospective randomised study.

Disagreement between fourth generation FloTrac and LiDCOrapid measurements of cardiac output and stroke volume variation during laparoscopic colectomy

STUDY OBJECTIVE

To determine the agreement between cardiac output (CO) and stroke volume variation (SVV) measured simultaneously by the fourth generation FloTrac/Vigileo system and LiDCOrapid system during pneumoperitoneum in patients undergoing laparoscopic colectomy.

DESIGN

Retrospective observational study.

SETTINGS

Operating room in a general hospital.

PATIENTS

Ten patients (American Society of Anesthesiologist 1 or 2) without preoperative anemia.

INTERVENTIONS

A 22-gauge catheter was inserted in the radial artery after induction of anesthesia. The arterial line was split to monitor CO and SVV simultaneously with the LiDCOrapid and fourth generation FloTrac/Vigileo systems. All data were downloaded from each system after surgery and simultaneous paired CO_FloTrac, CO_LiDCO and SVV_FloTrac, SVV_LiDCO values estimated every 1 minute during the pneumoperitoneum were analyzed.

MEASUREMENTS

To assess the agreement after carbon dioxide insufflation, a scatter 4-quadrant plot was generated using paired ΔCO values (changes in CO_FloTrac and CO_LiDCO just before pneumoperitoneum and 3 minutes after the induction of pneumoperitoneum). For data in which SVV_FloTrac was >9% but <16% and cardiac index measured by FloTrac/Vigileo was <2.5 L/min per m² during stable pneumoperitoneum (the period from 5 minutes after Trendelenburg position until discontinuation of pneumoperitoneum), simultaneously measured paired SVV_FloTrac and SVV_LiDCO were plotted every 1 minute using the Bland-Altman method.

MAIN RESULTS

A concordance ratio for changes in CO after the induction of pneumoperitoneum was 83% in 4-quadrant plot. During stable pneumoperitoneum, 702 paired SVV_FloTrac and SVV_LiDCO matched the criteria. These data sets were plotted by the Bland-Altman method and the bias and 95% limit of agreement of SVV were 2.01 and -2.63% to 6.65%, respectively, with 38% percentage error. The regression equation was SVV_LiDCO = 0.98 × SVV_FloTrac- 1.73 with Pearson correlation coefficient of 0.55.

CONCLUSIONS

Our study showed disagreement between the 2 methods and the hemodynamic parameters measured by one of the two devices should be interpreted with caution before therapeutic interventions.

Agreement between Pleth Variability Index and oesophageal Doppler to predict fluid responsiveness

BACKGROUND

Optimisation of stroke volume using oesophageal Doppler is an established technique to guide intraoperative fluid therapy. The method has practical limitations and therefore alternative indices of fluid responsiveness, such as ventilator-induced variation in the pulse oximetric signal (Pleth Variability Index (PVI)) could be considered. We hypothesised that both methods predict fluid responsiveness in a similar way.

METHODS

Seventy-five patients scheduled for open major abdominal surgery were randomised to fluid optimisation using fluid bolus algorithms based on either PVI (n = 35) or Doppler (n = 39). All patients were monitored with both methods; the non-guiding method was blind. Primary endpoint was the concordance between the methods to predict fluid responsiveness. We also analysed the ability of each method to predict a stroke volume increase ≥ 10% after a fluid bolus, as well as the accumulated intraoperative bolus fluid volume.

RESULTS

PVI indicated a need for fluid in one-third of the situations when Doppler did so, Cohen's kappa = 0.03. A fluid bolus indicated by the PVI algorithm increased stroke volume by ≥ 10% in half the situations. The same was found for the Doppler algorithm. The mean total bolus volume given was 878 ml when the fluid management was governed by PVI compared to 826 ml with Doppler (P = 0.71).

CONCLUSION

PVI- and Doppler-based stroke volume optimisations agreed poorly, which did not affect the amount of fluid administered. None of the algorithms showed a good ability to predict fluid responsiveness. Our results do not support the fluid responsiveness concept.

Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

Purpose

The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system.

Patients and methods

After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups.

Results

In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV.

Conclusion

Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD.

Effect of fluid loading with normal saline and 6% hydroxyethyl starch on stroke volume variability and left ventricular volume

Purpose

The aim of this clinical trial was to investigate changes in stroke volume variability (SVV) and left ventricular end-diastolic volume (LVEDV) after a fluid bolus of crystalloid or colloid using real-time three-dimensional transesophageal echocardiography (3D-TEE) and the Vigileo-FloTrac™ system.

Materials and methods

After obtaining Institutional Review Board approval, and informed consent from the research participants, 22 patients undergoing scheduled peripheral vascular bypass surgery were enrolled in the study. The patients were randomly assigned to receive 500 mL of hydroxyethyl starch (HES; HES group, n=11) or normal saline (Saline group, n=11) for fluid replacement therapy. SVV was measured using the Vigileo-FloTrac system. LVEDV, stroke volume, and cardiac output were measured by 3D-TEE. The measurements were performed over 30 minutes before and after the fluid bolus in both groups.

Results

SVV significantly decreased after fluid bolus in both groups (HES group, 14.7%±2.6% to 6.9%±2.7%, P<0.001; Saline group, 14.3%±3.9% to 8.8%±3.1%, P<0.001). LVEDV significantly increased after fluid loading in the HES group (87.1±24.0 mL to 99.9±27.2 mL, P<0.001), whereas no significant change was detected in the Saline group (88.8±17.3 mL to 91.4±17.6 mL, P>0.05). Stroke volume significantly increased after infusion in the HES group (50.6±12.5 mL to 61.6±19.1 mL, P<0.01) but not in the Saline group (51.6±13.4 mL to 54.1±12.8 mL, P>0.05). Cardiac output measured by 3D-TEE significantly increased in the HES group (3.5±1.1 L/min to 3.9±1.3 L/min, P<0.05), whereas no significant change was seen in the Saline group (3.4±1.1 L/min to 3.3±1.0 L/min, P>0.05).

Conclusion

Administration of colloid and crystalloid induced similar responses in SVV. A higher plasma-expanding effect of HES compared to normal saline was demonstrated by the significant increase in LVEDV.

Evaluation of stroke volume variation and pulse pressure variation as predictors of fluid responsiveness in patients undergoing protective one-lung ventilation

In order to investigate whether the hemodynamic indices, including stroke volume variation (SVV) and pulse pressure variation (PPV) could predict fluid responsiveness in patients undergoing protective one-lung ventilation. 60 patients scheduled for a combined thoracoscopic and laparoscopic esophagectomy were enrolled and randomized into two groups. The patients in the protective group (Group P) were ventilated with a tidal volume of 6 mL/kg, an inspired oxygen fraction (FiO2) of 80%, and a positive end expiratory pressure (PEEP) of 5 cm H2O. Patients in the conventional group (Group C) were ventilated with a tidal volume of 8 mL/kg and a FiO2 of 100%. Dynamic variables were collected before and after fluid loading (7 mL/kg hydroxyethyl starch 6%, 0.4 mL/kg/min). Patients whose stroke volume index (SVI) increased by more than 15% were defined as responders. Data collected from 45 patients were finally analyzed. Twelve of 24 patients in Group P and 10 of 21 patients in Group C were responders. SVV and PPV significantly changed after the fluid loading. The receive operating characteristic (ROC) analysis showed that the thresholds for SVV and PPV to discriminate responders were 8.5% for each, with a sensitivity of 66.7% (SVV) and 75% (PPV) and a specificity of 50% (SVV) and 83.3% (PPV) in Group P. However, the thresholds for SVV and PPV were 8.5% and 7.5% with a sensitivity of 80% (SVV) and 90% (PPV) and a specificity of 70% (SVV) and 80% (PPV) in Group C. We found SVV and PPV could predict fluid responsiveness in protective one-lung ventilation, but the accuracy and ability of SVV and PPV were weak compared with the role they played in a conventional ventilation strategy.

Oesophageal Doppler cardiac output monitoring: a longstanding tool with evolving indications and applications

Much work has been done over the years to assess cardiac output and better grasp haemodynamic profiles of patients in critical care and during major surgery. Pulmonary artery catheterization has long been considered as the standard of care, especially in critical care environments, however this dogma has been challenged over the last 10-15 years. This has led to a greater focus on alternate, lesser invasive technologies. This review focuses on the scientific and clinical outcomes basis of oesophageal Doppler monitoring. The science underpinning Doppler shift assessment of velocity stretches back over 100 years, whereas the clinical applicability, and specifically clinical outcomes improvement can be attributed to the last 20 years. Oesophageal Doppler monitoring (ODM), and its associated protocol-guided fluid administration, has been shown to reduce complications, length of stay, and overall healthcare cost when incorporated into perioperative fluid management algorithms. However, more recent advances in enhanced recovery after surgery programs have led to similar improvements, leading the clinician to consider the role of Oesophageal Doppler Monitor to be more focused in high-risk surgery and/or the high-risk patient.

Four phases of intravenous fluid therapy: a conceptual model

I.V. fluid therapy plays a fundamental role in the management of hospitalized patients. While the correct use of i.v. fluids can be lifesaving, recent literature demonstrates that fluid therapy is not without risks. Indeed, the use of certain types and volumes of fluid can increase the risk of harm, and even death, in some patient groups. Data from a recent audit show us that the inappropriate use of fluids may occur in up to 20% of patients receiving fluid therapy. The delegates of the 12th Acute Dialysis Quality Initiative (ADQI) Conference sought to obtain consensus on the use of i.v. fluids with the aim of producing guidance for their use. In this article, we review a recently proposed model for fluid therapy in severe sepsis and propose a framework by which it could be adopted for use in most situations where fluid management is required. Considering the dose-effect relationship and side-effects of fluids, fluid therapy should be regarded similar to other drug therapy with specific indications and tailored recommendations for the type and dose of fluid. By emphasizing the necessity to individualize fluid therapy, we hope to reduce the risk to our patients and improve their outcome.

Medical devices for the anesthetist: current perspectives

Anesthesiologists are unique among most physicians in that they routinely use technology and medical devices to carry out their daily activities. Recently, there have been significant advances in medical technology. These advances have increased the number and utility of medical devices available to the anesthesiologist. There is little doubt that these new tools have improved the practice of anesthesia. Monitoring has become more comprehensive and less invasive, airway management has become easier, and placement of central venous catheters and regional nerve blockade has become faster and safer. This review focuses on key medical devices such as cardiovascular monitors, airway equipment, neuromonitoring tools, ultrasound, and target controlled drug delivery software and hardware. This review demonstrates how advances in these areas have improved the safety and efficacy of anesthesia and facilitate its administration. When applicable, indications and contraindications to the use of these novel devices will be explored as well as the controversies surrounding their use.

Dehydration, hemodynamics and fluid volume optimization after induction of general anesthesia

OBJECTIVES

Fluid volume optimization guided by stroke volume measurements reduces complications of colorectal and high-risk surgeries. We studied whether dehydration or a strong hemodynamic response to general anesthesia increases the probability of fluid responsiveness before surgery begins.

METHODS

Cardiac output, stroke volume, central venous pressure and arterial pressures were measured in 111 patients before general anesthesia (baseline), after induction and stepwise after three bolus infusions of 3 ml/kg of 6% hydroxyethyl starch 130/0.4 (n=86) or Ringer's lactate (n=25). A subgroup of 30 patients who received starch were preloaded with 500 ml of Ringer's lactate. Blood volume changes were estimated from the hemoglobin concentration and dehydration was estimated from evidence of renal water conservation in urine samples.

RESULTS

Induction of anesthesia decreased the stroke volume to 62% of baseline (mean); administration of fluids restored this value to 84% (starch) and 68% (Ringer's). The optimized stroke volume index was clustered around 35-40 ml/m2/beat. Additional fluid boluses increased the stroke volume by ≥10% (a sign of fluid responsiveness) in patients with dehydration, as suggested by a low cardiac index and central venous pressure at baseline and by high urinary osmolality, creatinine concentration and specific gravity. Preloading and the hemodynamic response to induction did not correlate with fluid responsiveness. The blood volume expanded 2.3 (starch) and 1.8 (Ringer's) times over the infused volume.

CONCLUSIONS

Fluid volume optimization did not induce a hyperkinetic state but ameliorated the decrease in stroke volume caused by anesthesia. Dehydration, but not the hemodynamic response to the induction, was correlated with fluid responsiveness.