High-risk Cardiac Surgical Patients Research Articles

The use of perioperative Impella 5.5 support in high-risk cardiac surgery: a retrospective cohort study.

Although the Impella device has an established role in high-risk percutaneous intervention and cardiogenic shock, its role in open cardiac surgery remains unclear. We undertook this study to better understand the role of Impella support in cardiac surgical intervention. This is a retrospective cohort study of consecutive patients who underwent cardiac surgery with surgically placed Impella 5.5 device support from October 2020 through June 2023. Patient charts were identified and systematically reviewed for relevant information. The primary outcome for this study was patient survival to discharge. Secondary outcomes included intraoperative survival, 30-day survival and 1-year survival. From 2020-2023, ten patients underwent open cardiac surgery with Impella 5.5 support. Five patients were male and the median age was 56.5 years [interquartile range (IQR), 52-63.8 years]. Three patients (30%) presented for isolated revascularization, 3 patients (30%) presented for single valve surgical intervention, 3 patients (30%) presented for revascularization and valve intervention, and 1 patient (10%) presented for multivalve intervention. The median ejection fraction (EF) of patients was 25% (IQR, 21.25-32.5%), the median Society of Thoracic Surgeons risk score was 4.32% (IQR, 1.73-11.06%). Of the patients, 40% underwent axillary cannulation while 60% had central cannulation. Intraoperative survival was 100%, survival to discharge was 90% and 30-day survival was 80%. Our study suggests the use of surgical Impella in high-risk cardiac surgical patients is associated with acceptable survival regardless of site or timing of cannulation. However, Impella usage is associated with significant morbidity. Further investigation is warranted to better understand which patients benefit perioperative Impella support.

Pecto-intercostal Fascial Plane Block: A Novel Technique for Analgesia in Patients with Sternal Dehiscence.

Sternal wound complications following sternotomy need a multidisciplinary approach in high-risk postoperative cardiac surgical patients. Poorly controlled pain during surgical management of such wounds increases cardiovascular stress and respiratory complications. Multimodal analgesia including intravenous opioids, non-opioid analgesics, and regional anesthesia techniques, like central neuraxial blocks and fascial plane blocks, have been described. Pecto-intercostal fascial plane block (PIFB), a novel technique, has been effectively used in patients undergoing cardiac surgery. Under ultrasound (US) guidance PIFB is performed with the aim of depositing local anesthetic between two superficial muscles, namely the pectoralis major muscle and the external intercostal muscle. The authors report a series of five cases where US-guided bilateral PIFB was used in patients undergoing sternal wound debridement. Patients had excellent analgesia intraoperatively as well as postoperatively for 24 hours with minimal requirement of supplemental analgesia. None of the patients experienced complications due to PIFB administration. The authors concluded that bilateral PIFB can be effectively used as an adjunct to multimodal analgesia with general anesthesia and as a sole anesthesia technique in selected cases of sternal wound debridement.

Impact of ketamine versus propofol for anesthetic induction on cognitive dysfunction, delirium, and acute kidney injury following cardiac surgery in elderly, high-risk patients.

Evaluate the effects of ketamine versus propofol when used for induction of anesthesia in elderly, high-risk cardiac surgical patients on postoperative complications including cognitive dysfunction, delirium, and acute kidney injury. Prospective, randomized study performed at a tertiary medical center. A total of 52 patients aged ≥70 and older presenting for complex cardiac surgery were randomized to receive either ketamine or propofol for induction of anesthesia. Patients underwent a battery of cognitive testing preoperatively and postoperatively and the incidence of delirium and acute kidney injury were measured. Norepinephrine (NEE) equivalents following induction were assessed for each group. A total of 49 patients were included, 25 in the ketamine group and 24 in the propofol group with 3 patients excluded from the analysis. No difference was found between groups in either postoperative cognitive dysfunction or delirium incidence. Acute kidney injury occurred in 6 (24%) patients in the ketamine group in 12 (50%) patients in the propofol group, but the difference did not meet statistical significance (P = 0.08; Relative Risk = 2.1, 95% CI 0.9-4.7). NEE equivalents were lower in the ketamine group, 9.6 ± 22.2 versus 32.7 ± 46.0, P < 0.03. The use of ketamine versus propofol for induction of anesthesia did not impact the incidence of postoperative cognitive dysfunction or delirium. Twice as many patients in the propofol group developed acute kidney injury, although not reaching statistical significance and warranting further investigation. In elderly, high-risk patients, ketamine was associated with a significantly reduced need for vasopressor support following induction.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Intraoperative hemoadsorption in high-risk patients with infective endocarditis.

BackgroundPostoperative sepsis is an important cause of morbidity and mortality in patients with infective endocarditis undergoing surgical therapy. Blood purification using hemoadsorption therapy shows promising results in the treatment of sepsis. In this study, the clinical effects of intraoperative hemoadsorption in high-risk patients with infective endocarditis were evaluated.MethodsEligible candidates were high-risk patients with infective endocarditis undergoing cardiac surgery between January 2014 and December 2019. Patients with intraoperative hemoadsorption (hemoadsorption) were compared to patients without hemoadsorption (control). The endpoints were the incidence of postoperative sepsis, sepsis-associated death and in-hospital mortality. Additionally, postoperative vasopressor need, systemic vascular resistance indices and Sequential Organ Failure Assessment (SOFA) scores were compared.ResultsAfter propensity score matching, 70 high-risk patients were included. Postoperative sepsis occurred in 14 patients in the hemoadsorption group and in 16 patients in the control group, p = 0.629. Four patients died due to postoperative sepsis in the hemoadsorption group, while 11 postoperative septic patients died in the control group, p = 0.041. In-hospital mortality was 34% in the hemoadsorption group versus 43% in the control group, p = 0.461. On ICU-admission and the first postoperative day, the cumulative vasopressor need was 0.17 versus 0.25 μg/kgBW/min, p = 0.123 and 0.06 versus 0.11 μg/kgBW/min, p = 0.037, and the systemic vascular resistance index was 1448 versus 941 dyn·s·cm-5, p = 0.013 and 1156 versus 858 dyn·s·cm-5, p = 0.110 in the hemoadsorption versus control group, respectively. Postoperative course of SOFA score normalized significantly (p = 0.01) faster in the hemoadsorption group.ConclusionsIn high-risk cardiac surgical patients with infective endocarditis, intraoperative hemoadsorption significantly reduced sepsis-associated mortality. Furthermore, intraoperative hemoadsorption resulted in significant faster recovery of hemodynamics and organ function. Intraoperative hemoadsorption seems to attenuate the severity of postoperative sepsis.

Contemporary outcomes of cardiac surgery patients supported by the intra-aortic balloon pump.

OBJECTIVESAlthough the intra-aortic balloon pump (IABP) has been the most widely adopted temporary mechanical support device in cardiac surgical patients, its use has declined. The current study aimed to evaluate the occurrence and predictors of early mortality and complication rates in contemporary cardiac surgery patients supported by an IABP.METHODSA multicentre, retrospective analysis was performed of all consecutive cardiac surgical patients receiving perioperative balloon pump support in 8 centres between January 2010 to December 2019. The primary outcome was early mortality, and secondary outcomes were balloon-associated complications. A multivariable binary logistic regression model was applied to evaluate predictors of the primary outcome.RESULTSThe study cohort consisted of 2615 consecutive patients. The median age was 68 years [25th percentile 61, 75th percentile 75 years], with the majority being male (76.9%), and a mean calculated 30-day mortality risk of 10.0%. Early mortality was 12.7% (n = 333), due to cardiac causes (n = 266), neurological causes (=22), balloon-related causes (n = 5) and other causes (n = 40). A composite end point of all vascular complications occurred in 7.2% of patients, and leg ischaemia was observed in 1.3% of patients. The most important predictors of early mortality were peripheral vascular disease [odds ratio (OR) 1.63], postoperative dialysis requirement (OR 10.40) and vascular complications (OR 2.57).CONCLUSIONSThe use of the perioperative IABP proved to be safe and demonstrated relatively low complication rates, particularly for leg ischaemia. As such, we believe that specialists should not be held back to use this widely available treatment in high-risk cardiac surgical patients when indicated.

Associated factors and clinical outcomes in mechanical circulatory support use in patients undergoing high risk on-pump cardiac surgery: Insights from the LEVO-CTS trial

We describe variables and outcomes associated with peri-operative mechanical circulatory support (MCS) utilization among patients enrolled in the Levosimendan in patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial. In the LEVO-CTS trial, MCS utilization (defined as intra-aortic balloon pump, extracorporeal membrane oxygenation, or surgical ventricular assist device) within 5 days of surgery was examined. The association between MCS use and outcomes including 90-day mortality, 30-day renal-replacement therapy, and hospital and critical stay length of stay were determined. Among the 849 patients from 70 centers randomized to levosimendan or placebo, 85 (10.0%) patients were treated with MCS (71 intra-aortic balloon pump, 7 extracorporeal membrane oxygenation, 7 ventricular assist device); with 89.4% started on post-operative day 0. Inter-institutional use ranged from 0% to 100%. Variables independently associated with MCS utilization included combined coronary artery bypass grafting and valve surgery (adjusted odds ratio [OR] 2.73, 95% confidence interval [CI] 1.70-4.37, P < .001), history of lung disease (OR 1.70, 95% CI 1.06-2.70, P=.029), and history of heart failure (OR 2.44, 95% CI 1.10-5.45, P=.027). Adjusted 90-day mortality (22.4% vs 4.1%, hazard ratio 6.11, 95% CI 3.95-9.44, P < .001) was higher, and median critical care length of stay (8.0 vs 4.0 days, P < .001) was longer in patients managed with MCS. In a randomized controlled trial of high-risk cardiac surgical patients in North America, we observed patient, and surgical variables associated with MCS utilization. MCS use was associated with a higher risk of post-operative mortality.

Journal-related Activities and Other Special Activities at the 2020 American Society of Anesthesiologists Meeting.

Journal-related Activities and Other Special Activities at the 2020 American Society of Anesthesiologists Meeting.

Uncommon Pathogens Causing Hospital-Acquired Infections in Postoperative Cardiac Surgical Patients

AbstractBacterial infections are common causes of sepsis in the intensive care units. However, usually a finite number of Gram-negative bacteria cause sepsis (mostly according to the hospital flora). Some organisms such as Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus are relatively common. Others such as Stenotrophomonas maltophilia, Chryseobacterium indologenes, Shewanella putrefaciens, Ralstonia pickettii, Providencia, Morganella species, Nocardia, Elizabethkingia, Proteus, and Burkholderia are rare but of immense importance to public health, in view of the high mortality rates these are associated with. Being aware of these organisms, as the cause of hospital-acquired infections, helps in the prevention, treatment, and control of sepsis in the high-risk cardiac surgical patients including in heart transplants. Therefore, a basic understanding of when to suspect these organisms is important for clinical diagnosis and initiating therapeutic options. This review discusses some rarely appearing pathogens in our intensive care unit with respect to the spectrum of infections, and various antibiotics that were effective in managing these bacteria.

Utilizing Technology for Optimization of Pain Management and Mobilization in High Risk Cardiac Surgical ICU Patients

Utilizing Technology for Optimization of Pain Management and Mobilization in High Risk Cardiac Surgical ICU Patients

Outcomes with intra-aortic balloon pump in high risk cardiac surgery patients

ABSTRACT Introduction: In high-risk cardiac surgical patients the intra-aortic balloon pump (IABP) is the most frequent used tool for temporary mechanical circulatory support during the perioperative phase. The effects of IABP are an increase in diastolic blood pressure, an improvement in coronary perfusion and a reduction of ventricular afterload, so it increases the stroke volume and cardiac output. Objective: To study the effect of preoperative use of intra-aortic balloon pump (IABP) on the outcome of high-risk patients that were subjected to coronary artery bypass graft (CABG) surgery. Methods: From June 2009 to June 2011. Group of 100 patients considered as high-risk patients were subjected to elective bypass cardiac surgery at our center. Forty patients subjected to preoperative IABP as a prophylactic measure and 60 patients were not subjected to IABP. This is retrospective study of prospectively collected data .The definition of High risk was the presence of two or more known risk factors. The patient’s outcome is compared regarding the predicted mortality of the Euro SCORE. The preoperative effect of IABP on the outcome, mortality and 30 days follow-up was statistically analyzed. Results: Forty patients subjected to preoperative IABP as prophylactic measure due to higher Euro SCORE-predicted mortality than other 60 patients did not subject to IABP(60% vs 40 %, P = ˂0.05). Seventy patients (70%) were male while (30%) were female with a mean age of 58.62 ± 9.65 years. Patients subjected to preoperative IABP had increased a percentage of hospital mortality (P = ˂0.05) but this percentage is relatively lower than predicted by Euro SCORE. Patients subjected to preoperative IABP had lower rate of postoperative complication (acute kidney insult (P = 0.045), cardiac surgical intensive care unit (CSICU) stay (P = 0.032) and decrease the need for postoperative inotrope (P = 0.046)) compared to patients without preoperative IABP use. Other complications postoperative were low and similar in both groups. Conclusions: We conclude that patients have high-risk CABG, the preoperative IABP in this group with higher predicted mortality was associated with a relative reduction than predicted by Euro score. The preoperative IABP in this group has a reliable and acceptable outcome on postoperative complications. Keywords: intra-aortic balloon pump, High Risk, Cardiac Surgery

Study of Mixed Venous Oxygen Saturation (SVO2) Measurement in High-Risk Cardiac Surgical Patients

Background: Postoperative haemodynamic complications are the leading cause of mortality in heart surgery. Early prediction of postoperative complications based on haemodynamic parameters is invaluable for timely intervention, and can influence the operative outcome. In developed countries, the use of Swan-Ganz catheter to monitor patients’ postoperative haemodynamic variables for predicting short-term risks has become a gold standard. In Vietnam, there are hundreds cases of cardiac surgery each year; however, there has been no report on monitoring patients’ haemodynamic state and its predictive power for short-term operative outcomes. This study reported using mixed venous oxygen saturation (SVO2) as a prognostic marker for short-term outcome in high-risk cardiac surgical patients at hospitals in Vietnam from 2013–2015.

Early Extubation Without Increased Adverse Events in High-Risk Cardiac Surgical Patients

Previous reports of early extubation after cardiac surgical procedures vary in the definition of "early" and may limit findings to patients with less preoperative risk. This study sought to determine whether an eight-tier multidisciplinary early extubation protocol with the goal of extubating within 6 hours postoperatively would be successful without increasing adverse events in patients with increased preoperative risk. Postoperative adult cardiac surgical patients in a tertiary care intensive care unit (n= 459) were analyzed 6 months before and 6 months after implementation of the protocol. The Society of Thoracic Surgeons (STS) risk scores were used as surrogate markers of risk. Patients with STS scores (n= 333) were stratified into four equal groups from lowest to highest score. A composite of acute renal failure, reintubation, stroke, and mortality was the primary outcome. Secondary outcomes included intensive care unit and hospital lengths of stay, reoperation, and sternal wound infection. In all patients, ventilation times were significantly decreased from a median of 7.4 hours to 5.7 hours after protocol implementation. When stratified by STS scores, higher-risk patients (groups 3 and 4) had the largest reduction in ventilation times from amedian of 9.2 hours to 5.7 hours (p < 0.0001) without asignificant increase in adverse events. The highest-risk patients (STS score >40%; n= 14) all had extubation times shorter than 6 hours after the protocol withno significant increase found in adverse events (p= 0.138). A prudent and diligent multifaceted early extubation protocol may be successful in high-risk cardiac surgical patients without an increase in adverse outcomes. A larger study is needed in the future to confirm the finding.

OUTCOMES WITH INTRA-AORTIC BALLOON PUMP IN HIGH RISK CARDIAC SURGERY PATIENTS

ABSTRACT Introduction: In high-risk cardiac surgical patients the intra-aortic balloon pump (IABP) is the most frequent used tool for temporary mechanical circulatory support during the perioperative phase. The effects of IABP are an increase in diastolic blood pressure, an improvement in coronary perfusion and a reduction of ventricular afterload, so it increases the stroke volume and cardiac output. Objective: To study the effect of preoperative use of intra-aortic balloon pump (IABP) on the outcome of high-risk patients that were subjected to coronary artery bypass graft (CABG) surgery. Methods: From June 2009 to June 2011. Group of 100 patients considered as high-risk patients were subjected to elective bypass cardiac surgery at our center. Forty patients subjected to preoperative IABP as a prophylactic measure and 60 patients were not subjected to IABP. This is retrospective study of prospectively collected data .The definition of High risk was the presence of two or more known risk factors. The patient’s outcome is compared regarding the predicted mortality of the Euro SCORE. The preoperative effect of IABP on the outcome, mortality and 30 days follow-up was statistically analyzed. Results: Forty patients subjected to preoperative IABP as prophylactic measure due to higher Euro SCORE-predicted mortality than other 60 patients did not subject to IABP(60% vs 40 %, P = ˂0.05). Seventy patients (70%) were male while (30%) were female with a mean age of 58.62 ± 9.65 years. Patients subjected to preoperative IABP had increased a percentage of hospital mortality (P = ˂0.05) but this percentage is relatively lower than predicted by Euro SCORE. Patients subjected to preoperative IABP had lower rate of postoperative complication (acute kidney insult (P = 0.045), cardiac surgical intensive care unit (CSICU) stay (P = 0.032) and decrease the need for postoperative inotrope (P = 0.046)) compared to patients without preoperative IABP use. Other complications postoperative were low and similar in both groups. Conclusions: We conclude that patients have high-risk CABG, the preoperative IABP in this group with higher predicted mortality was associated with a relative reduction than predicted by Euro score. The preoperative IABP in this group has a reliable and acceptable outcome on postoperative complications. Keywords: intra-aortic balloon pump, High Risk, Cardiac Surgery

Assessment of changes in blood glucose concentration with intravascular microdialysis.

Blood glucose and its variability of is a major prognostic factor associated with morbidity. We hypothesized that intravenous microdialysis incorporated in a central venous catheter (CVC) would be interchangeable with changes in blood glucose measured by the reference method using a blood gas analyzer. Microdialysis and central venous blood glucose measurements were simultaneously recorded in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression and the Bland-Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in blood glucose measurement were evaluated by four-quadrant plot and trend interchangeability methods (TIM). In the 23 patients analyzed, the CVC was used as part of standard care with no complications. The correlation coefficient for absolute values (N = 99) was R = 0.91 (P < 0.001). The bias, precision and limits of agreement were - 9.1, 17.4 and - 43.2 to 24.9mg/dL, respectively. The concordance rate for changes in blood glucose measurements (N = 77) was 85% with the four-quadrant plot. The TIM showed that 14 (18%) changes of blood glucose measurements were uninterpretable. Among the remaining 63 (82%) interpretable changes, 23 (37%) were interchangeable, 13 (20%) were in the gray zone, and 27 (43%) were not interchangeable. Microdialysis using a CVC appears to provide imprecise absolute blood glucose values with risk of insulin misuse. Moreover, onlyone third of changes in blood glucose measurements were interchangeable with the reference method using the TIM.

Microvascular Responsiveness to Pulsatile and Nonpulsatile Flow During Cardiopulmonary Bypass

Pulsatile perfusion may offer microcirculatory advantages over conventional nonpulsatile perfusion during cardiopulmonary bypass (CPB). Here, we present direct visual evidence of microvascular perfusion and vasoreactivity between perfusion modalities. A prospective, randomized cohort study of 20 high-risk cardiac surgical patients undergoing pulsatile (n= 10) or nonpulsatile (n= 10) flow during CPB was conducted. Changes in sublingual mucosal microcirculation were assessed with orthogonal polarization spectral imaging along with near-infrared spectroscopic indices of thenar muscle tissue oxygen saturation (StO2) and its recovery during a vascular occlusion test at the following time points: baseline (T0), 30 minutes on CPB (T1), 90 minutes on CPB (T2), 1 hour after CPB (T3), and 24 hours after CPB (T4). On the basis of our scoring scale, a shift in microcirculatory blood flow occurred over time. The pulsatile group maintained normal perfusion characteristics, whereas the nonpulsatile group exhibited deterioration in perfusion during CPB (T2: 74.0% ± 5.6% versus 57.6% ± 5.0%) and after CPB (T3: 76.2% ± 2.7% versus 58.9% ± 5.2%, T4: 85.7% ± 2.6% versus 69.8% ± 5.9%). Concurrently, no important differences were found between groups in baseline StO2 and consumption slope at all time points. Reperfusion slope was substantially different between groups 24 hours after CPB (T4: 6.1% ± 0.6% versus 3.7% ± 0.5%), indicating improved microvascular responsiveness in the pulsatile group versus the nonpulsatile group. Pulsatility generated by the roller pump during CPB improves microcirculatory blood flow and tissue oxygen saturation compared with nonpulsatile flow in high-risk cardiac surgical patients, which may reflect attenuation of the systemic inflammatory response and ischemia-reperfusion injury.

Prophylaxis of postoperative nausea and vomiting after cardiac surgery in high-risk patients: A randomized controlled study.

Context:The role of prophylaxis for postoperative nausea and vomiting (PONV) in cardiac surgery is under debate.Aims:To study the risk factors for PONV after cardiac surgery and the role of betamethasone with or without droperidol for its prevention.Setting and Design:Randomized open-label controlled study comparing standard care with PONV prophylaxis from February to November 2016.Methods:Five hundred and two patients with planned nonemergent cardiac surgery were included. Interventions: In the intervention arm, PONV prophylaxis (4 mg betamethasone with/without 0.625 mg droperidol) was administered in high-risk patients (two or more risk factors). Patients in the control arm were treated as per routine hospital practices.Results:Female sex, past history of PONV, and migraines were associated with a significantly increased risk of PONV, while motion sickness, smoking status, and volatile anesthetics were not. Pain and treatment with nefopam or ketoprofen were associated with an increased risk of PONV. PONV was less frequent in the active arm compared to controls (45.5% vs. 54.0%, P = 0.063; visual analogic scale 10.9 vs. 15.3 mm, P = 0.043). Among the 180 patients (35.6%) with ≥2 risk factors, prophylaxis was associated with reduced PONV (intention-to-treat: 46.8% vs. 67.8%, P = 0.0061; per-protocol: 39.2% vs. 69%, P = 0.0002). In multivariate analysis, prophylaxis was independently associated with PONV (odds ratio [OR]: 0.324, 95% confidence interval: 0.167–0.629, P = 0.0009), as were female sex, past history of PONV, and migraines (OR: 3.027, 3.031, and 2.160 respectively). No drug-related side effects were reported.Conclusion:Betamethasone with/without droperidol was effective in decreasing PONV in high risk cardiac surgical patients without any side effect.

Mixed Venous Oxygen Saturation Predicts Short-term Outcome in High-risk Cardiac Surgical Patients

Mixed Venous Oxygen Saturation Predicts Short-term Outcome in High-risk Cardiac Surgical Patients

Mixed Venous Oxygen Saturation Predicts Short-term Outcome in High-risk Cardiac Surgical Patients

Mixed Venous Oxygen Saturation Predicts Short-term Outcome in High-risk Cardiac Surgical Patients

Assessment of changes in lactate concentration with intravascular microdialysis during high-risk cardiac surgery using the trend interchangeability method

BackgroundBlood lactate is a strong predictor of mortality, and repeated blood lactate assays are recommended during surgery in high-risk patients. We hypothesized that the use of intravascular microdialysis incorporated in a central venous catheter would be interchangeable with the reference blood gas technique to monitor changes in blood lactate. MethodsMicrodialysis and central venous blood lactate measurements were recorded simultaneously in high-risk cardiac surgical patients. The correlation between absolute values was determined by linear regression, and the Bland–Altman test for repeated measurements was used to compare bias, precision, and limits of agreement. Changes in lactate measurements were evaluated with a four-quadrant plot and trend interchangeability method (TIM). ResultsIn the 23 patients analysed, the central venous catheter was used as part of standard care, with no complications. The correlation coefficient for absolute values (n=104) was 0.96 (P<0.0001). The bias, precision, and limits of agreement were −0.19, 0.51, and −1.20 to 0.82 mmol litre−1, respectively. The concordance rate for changes in blood lactate measurements (n=80) was 94% with the four-quadrant plot. In contrast, the TIM showed that 23 (29) changes in lactate measurements were not interpretable, and among the remaining 57 (71) interpretable changes, 18 (32) were interchangeable, 8 (14) were in the grey zone, and 31 (54) were not interchangeable. ConclusionsMicrodialysis with a central venous catheter appears to provide reliable absolute blood lactate values. Although changes in blood lactate measurements showed an excellent concordance rate, changes between the two methods were poorly interchangeable with the TIM. Clinical trial registrationNCT02296593.