Hemodynamic parameters to guide fluid therapy

The clinical determination of the intravascular volume can be extremely difficult in critically ill and injured patients as well as those undergoing major surgery. This is problematic because fluid loading is considered the first step in the resuscitation of hemodynamically unstable patients. Yet, multiple studies have demonstrated that only approximately 50% of hemodynamically unstable patients in the intensive care unit and operating room respond to a fluid challenge. Whereas under-resuscitation results in inadequate organ perfusion, accumulating data suggest that over-resuscitation increases the morbidity and mortality of critically ill patients. Cardiac filling pressures, including the central venous pressure and pulmonary artery occlusion pressure, have been traditionally used to guide fluid management. However, studies performed during the past 30 years have demonstrated that cardiac filling pressures are unable to predict fluid responsiveness. During the past decade, a number of dynamic tests of volume responsiveness have been reported. These tests dynamically monitor the change in stroke volume after a maneuver that increases or decreases venous return (preload) and challenges the patients' Frank-Starling curve. These dynamic tests use the change in stroke volume during mechanical ventilation or after a passive leg raising maneuver to assess fluid responsiveness. The stroke volume is measured continuously and in real-time by minimally invasive or noninvasive technologies, including Doppler methods, pulse contour analysis, and bioreactance

Anesthesia advanced circulatory life support

The constellation of advanced cardiac life support (ACLS) events, such as gas embolism, local anesthetic overdose, and spinal bradycardia, in the perioperative setting differs from events in the pre-hospital arena. As a result, modification of traditional ACLS protocols allows for more specific etiology-based resuscitation. Perioperative arrests are both uncommon and heterogeneous and have not been described or studied to the same extent as cardiac arrest in the community. These crises are usually witnessed, frequently anticipated, and involve a rescuer physician with knowledge of the patient's comorbidities and coexisting anesthetic or surgically related pathophysiology. When the health care provider identifies the probable cause of arrest, the practitioner has the ability to initiate medical management rapidly. Recommendations for management must be predicated on expert opinion and physiological understanding rather than on the standards currently being used in the generation of ACLS protocols in the community. Adapting ACLS algorithms and considering the differential diagnoses of these perioperative events may prevent cardiac arrest

Fluid challenges in intensive care: the FENICE study A global inception cohort study

Fluid challenges (FCs) are one of the most commonly used therapies in critically ill patients and represent the cornerstone of hemodynamic management in intensive care units. There are clear benefits and harms from fluid therapy. Limited data on the indication, type, amount and rate of an FC in critically ill patients exist in the literature. The primary aim was to evaluate how physicians conduct FCs in terms of type, volume, and rate of given fluid; the secondary aim was to evaluate variables used to trigger an FC and to compare the proportion of patients receiving further fluid administration based on the response to the FC.This was an observational study conducted in ICUs around the world. Each participating unit entered a maximum of 20 patients with one FC.2213 patients were enrolled and analyzed in the study. The median [interquartile range] amount of fluid given during an FC was 500 ml (500-1000). The median time was 24 min (40-60 min), and the median rate of FC was 1000 [500-1333] ml/h. The main indication for FC was hypotension in 1211 (59 %, CI 57-61 %). In 43 % (CI 41-45 %) of the cases no hemodynamic variable was used. Static markers of preload were used in 785 of 2213 cases (36 %, CI 34-37 %). Dynamic indices of preload responsiveness were used in 483 of 2213 cases (22 %, CI 20-24 %). No safety variable for the FC was used in 72 % (CI 70-74 %) of the cases. There was no statistically significant difference in the proportion of patients who received further fluids after the FC between those with a positive, with an uncertain or with a negatively judged response.The current practice and evaluation of FC in critically ill patients are highly variable. Prediction of fluid responsiveness is not used routinely, safety limits are rarely used, and information from previous failed FCs is not always taken into account

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

The Ability of esCCO and ECOM Monitors to Measure Trends in Cardiac Output During Alveolar Recruitment Maneuver After Cardiac Surgery: A Comparison with the Pulmonary Thermodilution Method

International audienceBACKGROUND: Alveolar recruitment maneuvers (ARMs) are known to improve perioperative morbidity but can transiently impact cardiac output (CO). This reproducible hemodynamic perturbation creates a clinical opportunity to test multiple devices during acute changes in CO. The objective of this study was to evaluate the ability of 2 minimally invasive CO monitors, the ECOM (Endotracheal Cardiac Output Monitor) and the esCCO (estimated Continuous Cardiac Output), to measure trends in CO during an ARM in postoperative cardiac surgical patients. METHODS: Twenty-seven mechanically ventilated patients were studied in the postoperative intensive care unit setting. Hemodynamic measurements were made at 3 distinct time points: (1) before an ARM at zero end-expiratory pressure; (2) during an ARM at 15 cm H2O positive end-expiratory pressure; and (3) after the ARM again at zero end-expiratory pressure. Reference CO was obtained from intermittent bolus thermodilution (TDco) using a pulmonary artery catheter. At each of the 3 time points, mean values of 3 CO measurements from each device were collected simultaneously, as well as the corresponding changes in arterial pressure. The coefficient of variation of the 3 sets for each patient at each time point allowed for the calculation of the precision error for each device. Differences between absolute values of CO using the 2 tested methods and TDco were assessed using a Bland-Altman plot. Additionally, the agreement and responsiveness of the changes in CO (DeltaTDco, DeltaESco, and DeltaECco for changes in TDco, esCCO, and ECOM, respectively) and mean arterial pressure (MAP) were assessed using both a 4-quadrant plot with the coefficient of correlation concordance (CCC) and a polar plot diagram. A polar concordance rate above 80% was considered clinically acceptable. RESULTS: Eighty-one sets of 3 CO values were analyzed. Precision error of TDco was approximately 5.1% (interquartile range: 2.8-7.1). Between esCCO and TDco, the mean bias was +0.7 L/min with limits of agreement of -2.1 L/min and +3.5 L/min. Between ECOM and TDco, the mean bias was +0.2 L/min with limits of agreement of -2.0 L/min and +2.4 L/min. The CCC between DeltaECco and DeltaTDco (0.82 [95% confidence interval (CI), 0.72-0.89]) was significantly higher (P = 0.0053) than the CCC between DeltaESco and DeltaTDco (0.42 [95% CI, 0.20-0.59]), but not statistically different (P = 0.16) than the CCC between DeltaMAP and DeltaTDco (0.69 [95% CI, 0.54-0.80]). Polar plot analysis showed an angular bias with radial agreement limits of -29 degrees +/- 38 degrees between DeltaESco and DeltaTDco and -15 degrees +/- 29 degrees between DeltaECco and DeltaTDco. Four-quadrant concordance rate was 81% (95% CI, 74-88) between DeltaESco and DeltaTDco and 100% between DeltaECco and DeltaTDco. Polar concordance rates were 41% (95% CI, 34-48) between DeltaESco and DeltaTDco and 85% (95% CI, 79-90) between DeltaECco and DeltaTDco. CONCLUSIONS: Compared to pulmonary artery catheter thermodilution, both ECOM and esCCO underestimate changes in CO during an ARM in postoperative cardiac surgical patients. However, DeltaECco is within the angular limits of acceptable agreement and may be as efficient as invasive arterial pressure monitoring to track CO changes. In contrast, esCCO is not able to adequately track CO in these specific conditions

Do we need a dedicated hemodynamic control team?

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Tissue hemoglobin monitoring is unable to follow variations of arterial hemoglobin during transitions from pulsatile to constant flow in cardiac surgery

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