RESUMEN

BACKGROUND: Hypotension during dialysis arises from vasomotor tone alterations and hypovolemia, with disrupted counterregulatory mechanisms in acute kidney injury (AKI) patients. This study investigated the predictive value of preload dependency, assessed by the passive leg raising (PLR) test, and arterial tone, measured by dynamic elastance (Eadyn), for intradialytic hypotension (IDH). METHODS: In this prospective observational study conducted in a tertiary hospital ICU, hemodynamic parameters were collected from critically ill AKI patients undergoing intermittent hemodialysis using the FloTrac/Vigileo system. Baseline measurements were recorded before KRT initiation, including the PLR test and Eadyn calculation. IDH was defined as mean arterial pressure (MAP) < 65 mmHg during dialysis. Logistic regression was used to identify predictors of IDH, and Kaplan-Meier analysis assessed 90-day survival. RESULTS: Of 187 patients, 27.3% experienced IDH. Preload dependency, identified by positive PLR test, was significantly associated with IDH (OR 8.54, 95% CI 5.25-27.74), while baseline Eadyn was not predictive of IDH in this cohort. Other significant predictors of IDH included norepinephrine use (OR 16.35, 95% CI 3.87-68.98) and lower baseline MAP (OR 0.96, 95% CI 0.94-1.00). IDH and a positive PLR test were associated with lower 90-day survival (p < 0.001). CONCLUSIONS: The PLR test is a valuable tool for predicting IDH in critically ill AKI patients undergoing KRT, while baseline Eadyn did not demonstrate predictive value in this setting. Continuous hemodynamic monitoring, including assessment of preload dependency, may optimize patient management and potentially improve outcomes. Further research is warranted to validate these findings and develop targeted interventions to prevent IDH.

RESUMEN

BACKGROUND: Assessment of dynamic parameters to guide fluid administration is one of the mainstays of current resuscitation strategies. Each test has its own limitations, but passive leg raising (PLR) has emerged as one of the most versatile preload responsiveness tests. However, it requires real-time cardiac output (CO) measurement either through advanced monitoring devices, which are not routinely available, or echocardiography, which is not always feasible. Analysis of the hepatic vein Doppler waveform change, a simpler ultrasound-based assessment, during a dynamic test such as PLR could be useful in predicting preload responsiveness. The objective of this study was to assess the diagnostic accuracy of hepatic vein Doppler S and D-wave velocities during PLR as a predictor of preload responsiveness. METHODS: Prospective observational study conducted in two medical-surgical ICUs in Chile. Patients in circulatory failure and connected to controlled mechanical ventilation were included from August to December 2023. A baseline ultrasound assessment of cardiac function was performed. Then, simultaneously, ultrasound measurements of hepatic vein Doppler S and D waves and cardiac output by continuous pulse contour analysis device were performed during a PLR maneuver. RESULTS: Thirty-seven patients were analyzed. 63% of the patients were preload responsive defined by a 10% increase in CO after passive leg raising. A 20% increase in the maximum S wave velocity after PLR showed the best diagnostic accuracy with a sensitivity of 69.6% (49.1-84.4) and specificity of 92.8 (68.5-99.6) to detect preload responsiveness, with an area under curve of receiving operator characteristic (AUC-ROC) of 0.82 ± 0.07 (p = 0.001 vs. AUC-ROC of 0.5). D-wave velocities showed worse diagnostic accuracy. CONCLUSIONS: Hepatic vein Doppler assessment emerges as a novel complementary technique with adequate predictive capacity to identify preload responsiveness in patients in mechanical ventilation and circulatory failure. This technique could become valuable in scenarios of basic hemodynamic monitoring and when echocardiography is not feasible. Future studies should confirm these results.

RESUMEN

A positive fluid balance may evolve to fluid overload and associate with organ dysfunctions, weaning difficulties, and increased mortality in ICU patients. We explored whether individualized fluid management, assessing fluid responsiveness via a passive leg-raising maneuver (PLR) before a spontaneous breathing trial (SBT), is associated with less extubation failure in ventilated patients with a high fluid balance admitted to the ICU after liver transplantation (LT). We recruited 15 LT patients in 2023. Their postoperative fluid balance was +4476 {3697, 5722} mL. PLR maneuvers were conducted upon ICU admission (T1) and pre SBT (T2). Cardiac index (CI) changes were recorded before and after each SBT (T3). Seven patients were fluid-responsive at T1, and twelve were responsive at T2. No significant differences occurred in hemodynamic, respiratory, and perfusion parameters between the fluid-responsive and fluid-unresponsive patients at any time. Fluid-responsive patients at T1 and T2 increased their CI during SBT from 3.1 {2.8, 3.7} to 3.7 {3.4, 4.1} mL/min/m2 (p = 0.045). All fluid-responsive patients at T2 were extubated after the SBTs and consolidated extubation. Two out of three of the fluid-unresponsive patients experienced weaning difficulties. We concluded that fluid-responsive patients post LT may start weaning earlier and achieve successful extubation despite a high postoperative fluid balance. This highlights the profound impact of personalized assessments of cardiovascular state on critical surgical patients.

RESUMEN

PURPOSE: The passive leg raising test (PLR) is a noninvasive method widely adopted to assess fluid responsiveness. We propose to explore if changes in the carotid flow assessed by echo-Doppler can predict fluid responsiveness after a PLR. METHODS: We conducted a performance diagnostic study in two intensive care units from Argentina between February and April 2022. We included patients with signs of tissular hypoperfusion that required fluid resuscitation. We labeled the patients as fluid responders when we measured, after a fluid bolus, an increase greater than 15% in the left ventricle outflow tract (LVOT) VTI in an apical 5-chamber view and we compared those results with the carotid flow (CF) velocity-time integral (VTI) from the left supraclavicular region in a semi-recumbent position and during the PLR. RESULTS: Of the 62 eligible patients, 50 patients (80.6%) were included. The area under the ROC curve for a change in CF VTI during the PLR test was 0.869 (95% CI 0.743-0.947). An increase of at least of 11% in the CF VTI with the PLR predicted fluid-responsiveness with a sensitivity of 77.3% (95% CI 54.6-92.2%) and specificity of 78.6% (95% CI 59-91.7%). The positive predictive value was 73.9% (95% CI 57.4-85.6%) and the negative predictive value was 81.5% (95% CI 66.5-90.7%). The positive likelihood ratio was 3.61 and the negative likelihood ratio was 0.29. CONCLUSION: An increase greater than 11% in CF VTI after a PLR may be useful to predict fluid responsiveness among critically ill patients.

Asunto(s)

RESUMEN

INTRODUCTION: Prediction of fluid responsiveness in acutely ill patients might be influenced by a number of clinical and technical factors. We aim to identify variables potentially modifying the operative performance of fluid responsiveness predictors commonly used in clinical practice. METHODS: A sensitive strategy was conducted in the Medline and Embase databases to search for prospective studies assessing the operative performance of pulse pressure variation, stroke volume variation, passive leg raising (PLR), end-expiratory occlusion test (EEOT), mini-fluid challenge, and tidal volume challenge to predict fluid responsiveness in critically ill and acutely ill surgical patients published between January 1999 and February 2023. Adjusted diagnostic odds ratios (DORs) were calculated by subgroup analyses (inverse variance method) and meta-regression (test of moderators). Variables potentially modifying the operative performance of such predictor tests were classified as technical and clinical. RESULTS: A total of 149 studies were included in the analysis. The volume used during fluid loading, the method used to assess variations in macrovascular flow (cardiac output, stroke volume, aortic blood flow, volume‒time integral, etc.) in response to PLR/EEOT, and the apneic time selected during the EEOT were identified as technical variables modifying the operative performance of such fluid responsiveness predictor tests (p < 0.05 for all adjusted vs. unadjusted DORs). In addition, the operative performance of fluid responsiveness predictors was also influenced by clinical variables such as the positive end-expiratory pressure (in the case of EEOT) and the dose of norepinephrine used during the fluid responsiveness assessment for PLR and EEOT (for all adjusted vs. unadjusted DORs). CONCLUSION: Prediction of fluid responsiveness in critically and acutely ill patients is strongly influenced by a number of technical and clinical aspects. Such factors should be considered for individual intervention decisions.

Asunto(s)

RESUMEN

PURPOSE: The passive leg raising test (PLR) produces a reversible increase in venous return and, if the patient's ventricles are preload dependent, in the cardiac output. As this effect occurs in seconds, the transthoracic echocardiography is optimal for its real time assessment. The utility of the PLR for monitoring fluid responsiveness through the measurement of the left ventricle outflow tract velocity-time integral (LVOT VTI) in an apical 5-chamber view is well stablished. To achieve this view in critically ill patients is often challenging. The aim of this study is to explore the accuracy for predicting fluid responsiveness of the change in the right ventricle outflow tract velocity-time integral (RVOT VTI) from a subcostal view during a PLR. METHODS: This is a diagnostic accuracy study carried out in two centers in Argentina. We included patients admitted to the intensive care unit from January 2022 to April 2022, that required fluid expansion due to signs of tissular hypoperfusion. We measured the RVOT VTI from a subcostal view in a semi-recumbent position and during the PLR, and the LVOT VTI in an apical 5-chamber view before and after a fluid bolus. If the LVOT VTI increased by 15% after the fluid bolus, the patients were considered fluid responders. RESULTS: We included 43 patients. The area under the ROC curve for a change in the RVOT VTI during the PLR was 0.879 (95% CI 0.744-0.959). A change of 15.36% in the RVOT VTI with the PLR predicted fluid responsiveness with a sensitivity of 85.7% (95% CI 57.2%-98.2%) and specificity of 93.1% (95% CI 77.2-99.2). The positive predictive value was 85.7% (95% CI 60.8%-95.9%) and the negative predictive value was 93.1% (95% CI 78.8%-98%). The positive likelihood ratio was 12.43 and the negative predictive value was 0.15. CONCLUSION: The RVOT VTI change during a PLR is suitable for the prediction of fluid responsiveness in critically ill patients.

RESUMEN

INTRODUCTION: Sepsis is a disease that is still associated with high mortality, in which timely interventions are related to better results. OBJECTIVE: To determine if there is a difference in in-hospital mortality, fluid balances, norepinephrine initiation and recovery time of blood pressure, when comparing the resuscitation of the patient who is admitted to the emergency room in septic shock by applying the ultrasound protocol (USER) versus the standard of care. PATIENTS AND METHODS: This is a prospective, cohort study conducted in the emergency room of a highly complex hospital of patients with septic shock. RESULTS: 83 patients recruited in total. The groups were comparable in demographics, mean baseline blood pressure, disease severity given by the SOFA value, and arterial lactate. A statistically significant difference was documented in the fluid balances at 4 hours, median 1325mL (IQR:451-2455mL) in Group C versus 900mL (IQR:440-1292) in Group U (p=0.048) and at 6 hours, median 1658mL (IQR:610-2925mL) versus 1107mL (IQR:600-1500mL), p=0.026, as well as in the total fluid balance of hospital stay, median 14,564mL (IQR:8660-18,705mL) versus 8660mL (IQR:5309-16,974mL), p=0.049. On the other hand, in the USER Group, the mean blood pressure ≥ 65mmHg was achieved in 97.4% of the patients 4 hours after the start of the protocol versus 50% in Group C (p=<0.001). Mortality with the use of the protocol compared with conventional therapy was (56.4% vs 61.36%, p=0.647). CONCLUSION: The use of the USER protocol in patients with septic shock in the emergency room showed lower fluid balances at 4 and 6 hours, and of the total hospital stay, as well as earlier initiation of norepinephrine and statistically significant faster improvement in blood pressure. Although a statistically significant difference was not found in the days of ICU stay, hospitalization and in-hospital mortality, a trend was observed in the reduction of these parameters.

RESUMEN

INTRODUCTION: Dynamic predictors of fluid responsiveness have shown good performance in mechanically ventilated patients at tidal volumes (Vt) > 8 mL kg-1. Nevertheless, most critically ill conditions demand lower Vt. We sought to evaluate the operative performance of several predictors of fluid responsiveness at Vt ≤ 8 mL kg-1 by using meta-regression and subgroup analyses. METHODS: A sensitive search was conducted in the Embase and MEDLINE databases. We searched for studies prospectively assessing the operative performance of pulse pressure variation (PPV), stroke volume variation (SVV), end-expiratory occlusion test (EEOT), passive leg raising (PLR), inferior vena cava respiratory variability (Δ-IVC), mini-fluid challenge (m-FC), and tidal volume challenge (VtC), to predict fluid responsiveness in adult patients mechanically ventilated at Vt ≤ 8 ml kg-1, without respiratory effort and arrhythmias, published between 1999 and 2020. Operative performance was assessed using hierarchical and bivariate analyses, while subgroup analysis was used to evaluate variations in their operative performance and sources of heterogeneity. A sensitivity analysis based on the methodological quality of the studies included (QUADAS-2) was also performed. RESULTS: A total of 33 studies involving 1,352 patients were included for analysis. Areas under the curve (AUC) values for predictors of fluid responsiveness were: for PPV = 0.82, Δ-IVC = 0.86, SVV = 0.90, m-FC = 0.84, PLR = 0.84, EEOT = 0.92, and VtC = 0.92. According to subgroup analyses, variations in methods to measure cardiac output and in turn, to classify patients as responders or non-responders significantly influence the performance of PPV and SVV (p < 0.05). Operative performance of PPV was also significantly affected by the compliance of the respiratory system (p = 0.05), while type of patient (p < 0.01) and thresholds used to determine responsiveness significantly affected the predictability of SVV (p = 0.05). Similarly, volume of fluids infused to determine variation in cardiac output, significantly affected the performance of SVV (p = 0.01) and PLR (p < 0.01). Sensitivity analysis showed no variations in operative performance of PPV (p = 0.39), SVV (p = 0.23) and EEOT (p = 0.15). CONCLUSION: Most predictors of fluid responsiveness reliably predict the response of cardiac output to volume expansion in adult patients mechanically ventilated at tidal volumes ≤ 8 ml kg-1. Nevertheless, technical and clinical variables might clearly influence on their operative performance.