P. Chiarandini

Arterial Pulse Cardiac Output Agreement With Thermodilution in Patients in Hyperdynamic Conditions

OBJECTIVE This study aimed to compare continuous cardiac output (CCO) obtained using the arterial pulse wave (APCO) measurement with a simultaneous measurement of the intermittent cardiac output (ICO) and CCO obtained with a pulmonary artery catheter (PAC) in liver transplant patients. DESIGN A prospective, single-center evaluation. SETTING A university hospital intensive care unit. PATIENTS Eighteen patients after liver transplantation. INTERVENTIONS Pulmonary artery catheters were placed in all patients, and ICO and CCO were determined using thermodilution. APCO measurements were made with the Vigileo System (Edwards Lifesciences, Irvine, CA). MEASUREMENTS AND MAIN RESULTS The authors obtained 126 data pairs of ICO and APCO and 864 pairs of CCO and APCO. ICO data were collected after intensive care unit admission and every 8 hours until the 48th postoperative hour. CCO and APCO data were collected every hour from admission until the 48th postoperative hour. Bias and precision were 0.95 +/- 1.41 L/min for ICO versus APCO and 1.29 +/- 1.28 L/min for CCO and APCO. Bias and precision for cardiac output (CO) data pairs less than 8 L/min were 0.32 +/- 1.14 L/min between ICO and APCO and 0.71 +/- 0.98 L/min between CCO and APCO. For CO data pairs higher than 8 L/min, bias and precision were 1.79 +/- 1.54 L/min between ICO and APCO and 2.25 +/- 1.14 L/min between CCO and APCO. CONCLUSIONS APCO enables the assessment of CO with clinically acceptable bias and precision. At higher CO levels, APCO underestimates PAC measurements and it is not as reliable as thermodilution in hyperdynamic liver transplant patients.

Uncalibrated Arterial Pulse Cardiac Output Measurements in Patients With Moderately Abnormal Left Ventricular Function

OBJECTIVE The aim of the study was to evaluate the accuracy and precision of the Vigileo/FloTrac system (Edwards Lifesciences, Irvine, CA) when compared with the intermittent cardiac output and continuous cardiac output measurements obtained from pulmonary arterial catheters in patients with moderately abnormal left ventricular function undergoing elective coronary artery bypass graft surgery. DESIGN A prospective, observational study. SETTING Tertiary university hospital. PARTICIPANTS Twenty patients with moderately abnormal left ventricular function undergoing coronary artery bypass graft surgery were enrolled. MEASUREMENTS AND RESULTS Data were collected before the induction of anesthesia (T1), after the induction of anesthesia (T2), before cardiopulmonary bypass with an open chest (T3), after cardiopulmonary bypass (T4), after sternal closure (T5), on intensive care unit admission (T6), and at 6 hours (T7) and 12 hours after surgery (T8). A total of 360 data measurements were collected; the mean bias between intermittent cardiac output (ICO) and arterial pressure cardiac output (APCO) was -0.50 ± 1.72 L/min, and the percentage error (PE) was 37.00%. The mean difference between CCO and APCO was -0.06 ± 1.84 L/min, and the PE was 37.80%. The correlation between ΔICO and ΔAPCO was r = 0.7; the correlation between ΔCCO and ΔAPCO was r = 0.73. In the intraoperative period, the mean bias between ICO and APCO was -0.41 ± 1.75 L/min, and the PE was 40.87%. The mean difference between CCO and APCO was -0.18 ± 1.90 L/min, and the PE was 41.48%. In the postoperative period, the mean bias between ICO and APCO was -0.56 ± 1.70 L/min, and the PE was 34.43%. The mean difference between CCO and APCO was -0.36 ± 1.76 L/min, and the PE was 34.87%. CONCLUSIONS In cardiac surgical patients with moderately abnormal left ventricular function, the Vigileo/FloTrac 2nd generation software sensor device showed mild intraoperative and postoperative agreement when compared with a pulmonary arterial catheter.

The Liver Transplant Recipient With Cardiac Disease

Liver transplantation is a stressful condition for the cardiovascular system of patients with advanced hepatic disease. The underlying hemodynamic and cardiac status of patients with cirrhosis is crucial to determine which patients should became recipients. Generally preoperative cardiovascular testing is performed on potential candidates who are more than 45 years old, or have diabetes mellitus, or peripheral vascular disease, or more than two standard cardiac risk factors. Recent data suggest that the prevalence of coronary artery disease among patients with cirrhosis is much greater than previously believed; it likely mirrors or exceeds the prevalence rate in the healthy population. The morbidity and mortality of patients with coronary artery disease who undergo orthotopic liver transplantation (OLT) without treatment are unacceptably high. In conclusion, accurate preoperative cardiac evaluation according to the new American Heart Association & American College of Cardiology should lead to detect and treat coronary artery disease before liver transplantation. In case of alcohol-related cardiomyopathy, portopulmonary hypertension, and hypertrophic cardiomyopathy, there should be a case-by-case discussion by the hepatologist and cardiologist to consider the patient for liver transplantation. No robust data are available on the impact of decompensated dilated heart failure in this setting. If a recipient with cardiac disease is scheduled for OLT, we strongly suggest advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography.

Circadian variations in cyclosporine C2 concentrations during the first 2 weeks after liver transplantation

The strategies currently used to monitor concentrations of cyclosporine (CsA) in transplanted patients include whole blood trough (C0), total or abbreviated area under the curve (AUC) concentration and population pharmacokinetic approaches. Recently, a single blood concentration measurement at 2 hours (C2) after CsA administration has been shown to be helpful to predict clinical effects during the first weeks after transplantation of liver and kidney grafts. However, this approach has raised multiple questions about pharmacokinetic variability, analytical methods, and organizational requirements. From a pharmacokinetic point of view, the variability of CsA blood concentrations may relate to circadian variations. The present study sought to characterize the circadian variation in C0 and C2 CsA levels among 20 liver transplant recipients during the first 2 weeks posttransplant. All patients received two equal oral doses of CsA microemulsion formulation every 12 hours. Blood samples were collected before and 2 hours after CsA administration in the morning (AM) and in the evening (PM). Whole blood concentrations of CsA were assayed using the monoclonal fluorescence polarization immunoassay system. During the first 2 weeks posttransplant, C2 AM mean levels were significantly higher than C2 PM levels (542 +/- 241 vs 383 +/- 182 ng/mL, P =.005), while the C0 AM mean level was not statistically different from the C0 PM (285 +/- 174 vs 223 +/- 124 ng/mL, P =.367). Our results suggest that morning CsA blood samples may afford a better approach to optimize the CsA dosage, especially based on C2 values.

Uncalibrated Continuous Cardiac Output Measurement in Liver Transplant Patients: LiDCOrapid™ System versus Pulmonary Artery Catheter

OBJECTIVE The aim of the study was to assess the level of agreement between continuous cardiac output estimated by uncalibrated pulse-power analysis (PulseCOLiR) and intermittent (ICO) and continuous cardiac output (CCO) obtained using a pulmonary artery catheter (PAC). DESIGN Prospective cohort study. SETTING University hospital intensive care unit. PARTICIPANTS Twenty patients after liver transplantation. INTERVENTION Pulmonary artery catheters were placed in all patients, and ICO and CCO were determined using thermodilution. PulseCOLiR measurements were made using a LiDCOrapid(TM) (LiDCO Ltd, Cambridge, UK). MEASUREMENTS AND MAIN RESULTS ICO data were determined after intensive care unit admission and every 8 hours until the 48th postoperative hour. CCO and PulseCOLiR measurements were recorded simultaneously at these same time intervals as well as hourly. For the 8-hour data set (140 data pairs), the mean bias and percentage errors (PE) were, respectively,-0.10 L/min and 39.2% for ICO versus PulseCOLiR and 0.79 L/min and 34.6% for CCO versus PulseCOLiR. For the hourly comparison of CCO versus PulseCOLiR (980 data pairs), the bias was 0.75 L/min and the PE 37%. To assess the ability to measure change, a 4-quadrant plot was produced for each pair of methods. The performance of PulseCOLiR was moderate in detecting changes in ICO. CONCLUSIONS In conclusion, the uncalibrated PulseCOLir method should not be used as a substitute for the thermodilution technique for the monitoring of cardiac output in liver transplant patients.

Prognostic Power of Pre- and Postoperative B-Type Natriuretic Peptide Levels in Patients Undergoing Abdominal Aortic Surgery

OBJECTIVES The first aim of the present study was to evaluate the pre- and postoperative B-type natriuretic peptide (BNP) levels in patients undergoing surgery for repair of an infrarenal abdominal aortic aneurysm (AAA) and analyze their power as a predictor of in-hospital cardiac events. The second aim was to evaluate the association among pre- and postoperative BNP levels, postoperative patient complications, and length of hospital stay. DESIGN Prospective observational study. SETTING A university hospital. PARTICIPANTS Forty-five patients undergoing elective surgery for an abdominal aortic aneurysm. INTERVENTIONS The plasma BNP level was assessed just before surgery and then on postoperative day 1. Cardiac troponin I levels were measured postoperatively on arrival to the intensive care unit (time 0) and then 12, 48, and 72 hours later. MEASUREMENTS AND MAIN RESULTS The preoperative BNP concentration in patients who developed an acute myocardial infarction was 209 (IQR 84-346) pg/mL compared with 74 (IQR 28-142) pg/mL in those who did not. The difference between groups was statistically significant (p = 0.04). The Spearman correlation showed that postoperative BNP levels correlated significantly with preoperative BNP levels (r = 0.73, p = 0.0001), length of hospital stay (r = 0.35, p = 0.04), and troponin I concentration at 0 hour (r = 0.42, p = 0.02), 12 hours (r = 0.51, p = 0.0052), and 48 hours (r = 0.40, p = 0.033). In contrast, preoperative BNP levels correlated with troponin I at only 12 hours (r = 0.34, p = 0.02). Postoperative BNP levels were influenced significantly by transfusions (p = 0.035) and cross-clamping times (p = 0.038). CONCLUSIONS The present results confirm the high negative predictive value of preoperative BNP levels; and postoperative BNP levels showed a better correlation with postoperative troponin levels, blood transfusion, and postoperative cardiac events.

Liver Transplant Quality and Safety Plan in Anesthesia and Intensive Care Medicine

Patients scheduled for orthotopic liver transplantation (OLT) may have coexisting diseases and more likely receive grafts of poorer quality than in the past. Perioperative mortality and morbidity are usually due to a combination of factors related to the patient, graft, surgery, anesthesia, and intensive care management. Anesthesia and intensive care are the areas with the highest frequency and severity of errors. Error and accident risks are always present in this context where a human component is unavoidable. The matter of medical errors is becoming noteworthy worldwide. Nevertheless, data concerning medical errors during OLT are not available in Italy. There are only hypothetical evaluations. The number of adverse events may be high, but so far no specific programs have been developed to increase patient safety. To improve patient safety, anesthesia and intensive care units must use a proactive approach dedicated to an OLT program. We have presented herein a prevention policy to detect errors before they happen through incident reporting, anonymous and voluntary reports of adverse events or near misses, operating room checklists (patient, drugs, devices, equipment), improved training, safer facilities, equipment function, and adequate drug supplies for an OLT program.

Hemodynamic Monitoring During Liver Transplantation.

Orthotopic liver transplantation (OLTx) is a surgical procedure that is currently performed to treat end-stage liver disease (ESLD) in selected patients. It was first performed by Starzl and colleagues in 1963 in a 3-year-old boy with biliary atresia, who died during surgery because of massive bleeding. The following 5 patients survived no longer than 23 days, and hence the transplantation program was stopped. In the following years, because of improvement in the surgical technique, organ support, and immunosuppressive therapy (discovery and introduction of cyclosporine), liver transplantation procedures restarted and were performed all over the world. In 2015 >6500 livers were transplanted in the United States (adult, pediatric, and living-related), with a survival of >70% after 5 years in adults. Despite the improvements reached over >50 years, liver transplantation is still a challenging procedure for both the surgeon and the anesthesiologist because of the hemodynamic, metabolic, and coagulative derangements that can occur during all phases of the procedure (hepatectomy, anhepatic, and reperfusion). To reduce waiting list mortality due to donor shortage, organ allocation in many countries is based on the concept of giving priority to the sickest patient. Therefore, candidates are often older, with more severe and complex hepatic disease than in the past. Large blood losses, rapid changes in venous return, and the need for inotropes and vasopressors are clinical problems still frequently encountered by anesthesiologists during OLTx. The best way to deal with these problems is through early diagnosis and goal-directed therapy by means of hemodynamic monitoring. Classic hemodynamics parameters,

Effects of Catecholamines on Microcirculation During General Inhalation Anesthesia

OBJECTIVE The aim of this study was to investigate the effects of clinical dosages of norepinephrine and dobutamine on sublingual microcirculation during general anesthesia with sevoflurane in minor surgical procedures. DESIGN This prospective study was performed on patients scheduled for breast cancer surgery. SETTING Tertiary care university hospital. PARTICIPANTS Twenty patients undergoing elective surgery. INTERVENTIONS Patients received a continuous infusion of norepinephrine (0.1 μg/kg/min) and afterwards, following a 15-minute interval, a continuous infusion of dobutamine (5 μg/kg/min). Prior to and at the end of each drug infusion period, hemodynamic parameters were measured using an esophageal Doppler probe (ED), and 5 sidestream darkfield (SDF) sublingual microcirculation video recordings were taken. MEASUREMENTS AND MAIN RESULTS No significant changes to total vessel density (TVD)(mm/mm(2)), perfused vessel density (PVD) (mm/mm(2)), proportion of perfused vessels (PPV) (percentage), or microvascular flow index (MFI) (arbitrary units) were measured at the end of each drug infusion period versus pre-infusion data and no differences were observed between the effects of norepinephrine versus dobutamine. Mean arterial pressure (APm) (mmHg) was significantly greater following both norepinephrine and dobutamine infusions compared to pre-infusion values, while peak velocity (PV) (cm/sec) and the stroke volume index (SVI) (mL/m(2)) only showed a significant increase following the dobutamine infusion. No change in corrected flow time (FTc) (msec) was observed. CONCLUSIONS During general anesthesia with sevoflurane, the infusion of clinical dosages of norepinephrine and dobutamine did not alter sublingual perfusion, although the expected systemic hemodynamic alterations were induced.

Perioperative Intra- and Extravascular Volume in Liver Transplant Recipients

UNLABELLED Assessing adequate volemia to avoid fluid overload and pulmonary edema perioperatively in liver transplantation (LT) is a challenge both for the anesthetist and the intensivist. Volumetric preload indices, such as intrathoracic blood volume index (ITBVI), measured by transpulmonary thermodilution, and continuous end-diastolic volume index (EDVI), measured by pulmonary artery thermodilution, were shown to better reflect preload than central venous pressure (CVP) or pulmonary artery occlusion pressure (PAOP). An ITBVI increase soon after the graft reperfusion influenced pulmonary perfusion without an alteration of extravascular lung water index (EVLWI) and without impaired oxygenation. This study was designed to evaluate relationships between CVP, PAOP, ITBVI, EDVI, and stroke volume index (SVI) within 48 hours after LT. We also investigated the relationship between EVLWI and arterial partial pressure of oxygen and inspired oxygen fraction ratio (PaO(2)/FiO(2)). METHODS We enrolled 125 patients (103 men and 22 women) undergoing LT. All patients were monitored with the PiCCO system (Pulsion Medical System) and with advanced pulmonary artery catheter connected to the Vigilance System. Hemodynamic-volumetric data were collected upon intensive care unit admission and every 8 hours up to 48 hours. Univariate and multivariate regression models were fitted to assess associations between SVI and EDVI, ITBVI, and filling pressures after adjusting for the right ventricular ejection fraction (RVEF, categorized as ≤30, 31-40, or >40) and the phase of the observation period. We also assessed associations between PaO(2)/FiO(2) and EVLWI. RESULTS SVI was associated with EDVI, ITBVI, and RVEF. The models showing the best fit to the data were those including EDVI and ITBVI. Neither CVP nor PAOP showed correlation with SVI. EVLWI inversely correlated with PaO(2)/FiO(2). CONCLUSIONS In the first 48 hours after LT, ITBVI and EDVI were associated with SVI assessment, whereas CVP and PAOP were not related. EVLWI significantly inversely correlated with PaO(2)/FiO(2).