Arterial Lactate Concentration Research Articles

Novel portable hypothermic machine perfusion preservation device enhances cardiac viability of donated human hearts.

Heart transplant remains the gold standard treatment for patients with advanced heart failure. However, the list of patients waiting for a heart transplant continues to increase. We have developed a portable hypothermic oxygenated machine perfusion device, the VP.S ENCORE®, to extend the allowable preservation time. The purpose of this study was to test the efficacy of the VP.S. ENCORE® using deceased donors derived hearts. Hearts from brain-dead donors not utilized for transplant (n = 11) were offered for research from the Texas Organ Sharing Alliance (TOSA), South and Central Texas' Organ Procurement Organization (OPO) and were preserved in the VP.S ENCORE® for 4 (n = 2), 6 (n = 3), and 8 (n = 3) hours or were kept in static cold storage (SCS) (n = 3). After preservation, the hearts were placed in an isolated heart Langendorff model for reperfusion and evaluated for cardiac function. The mean donor age was 37.82 ± 12.67 with the youngest donor being 19 and the oldest donor being 58 years old. SCS hearts mean weight gain (%) was -1.4 ± 2.77, while perfused at 4 h was 5.6 ± 6.04, perfused at 6 h 2.1 ± 6.04, and 8 h was 7.2 ± 10.76. Venous and arterial lactate concentrations were less than 2.0 mmol/L across all perfused hearts. Left ventricular contractility (+dPdT, mmHg/s) for 4 h (1,214 ± 1,064), 6 (1,565 ± 141.3), and 8 h (1,331 ± 403.6) were within the range of healthy human heart function. Thus, not significant as compared to the SCS group (1,597 ± 342.2). However, the left ventricular relaxation (mmHg/s) was significant in 6-hour perfused heart (p < 0.05) as compared to SCS. Gene expression analysis of inflammation markers (IL-6, IL-1β) showed no significant differences between SCS and perfused hearts, but a 6-hour perfusion led to a downregulated expression of these markers. The results demonstrate that the VP.S ENCORE® device enhances cardiac viability and exhibits comparable cardiac function to a healthy heart. The implications of these findings suggest that the VP.S ENCORE® could introduce a new paradigm in the field of organ preservation, especially for marginal hearts.

Effect of early peri-operative arterial lactate concentration level ratios on post-hepatectomy liver failure

BackgroundPost-hepatectomy liver failure (PHLF) is a serious complication after hepatectomy and a major cause of death. The current criteria for PHLF diagnosis (ISGLS consensus) require laboratory data of elevated INR level and hyperbilirubinemia on or after postoperative day 5. This study aims to propose a new indicator for the early clinical prediction of PHLF.MethodsThe peri-operative arterial lactate concentration level ratios were derived from time points within the 3 days before surgery and within POD1, the patients were divided into two groups: high lactate ratio group (≥ 1) and low lactate ratio group (< 1). We compared the differences in morbidity rates between the two groups. Utilized logistic regression analysis to identify the risk factors associated with PHLF development and ROC curves to compare the predictive value of lactate ratio and other liver function indicators for PHLF.ResultsA total of 203 patients were enrolled in the study. Overall morbidity and severe morbidity occurred in 64.5 and 12.8 per cent of patients respectively. 39 patients (19.2%) met the criteria for PHLF, including 15 patients (7.4%) with clinically relevant Post-hepatectomy liver failure (CR-PHLF). With a significantly higher incidence of PHLF observed in the lactate ratio ≥ 1 group compared to the lactate ratio < 1 group (n = 34, 26.8% vs. n = 5, 6.6%, P < 0.001). Multivariable logistic regression analysis revealed that a lactate ratio ≥ 1 was an independent predictor for PHLF (OR: 3.239, 95% CI 1.097–9.565, P = 0.033). Additionally, lactate ratio demonstrated good predictive efficacy for PHLF (AUC = 0.792).ConclusionsEarly assessment of peri-operative arterial lactate concentration level ratios may provide experience in early intervention of complications in patients with hepatocellular carcinoma, which can reduce the likelihood of PHLF occurrence and improve patient prognosis.

Markers of Tissue Perfusion as Predictors of Adverse Outcomes in Patients with Left Ventricular Dysfunction Undergoing Coronary Artery Bypass Surgery.

Cardiac surgery patients may be exposed to tissue hypoperfusion and anaerobic metabolism. To verify whether the biomarkers of tissue hypoperfusion have predictive value for prolonged intensive care unit (ICU) stay in patients with left ventricular dysfunction who underwent coronary artery bypass surgery. After approval by the institution's Ethics Committee and the signing of informed consent, 87 patients with left ventricular dysfunction (ejection fraction < 50%) undergoing coronary artery bypass surgery were enrolled. Hemodynamic and metabolic biomarkers were collected at five time points: after anesthesia, at the end of the surgery, at ICU admission, and at six and twelve hours after. An analysis of variance for repeated measures followed by a Bonferroni post hoc test was used for repeated, continuous variables (hemodynamic and metabolic variables) to determine differences between the two groups over the course of the study period. The level of statistical significance adopted was 5%. Thirty-eight patients (43.7%) who presented adverse outcomes were older, higher Euro score (p<0.001), and elevated ΔpCO2 as analyzed 12 hours after ICU admission (p<0.01), while increased arterial lactate concentration at 6 hours postoperatively was found to be a negative predictive factor (p<0.01). Euro SCORE, six-hour postoperative arterial lactate, 12-hour postoperative ΔPCO2, and eRQ are independent predictors of adverse outcomes in patients with left ventricular dysfunction after cardiac surgery.

Umbilical arterial lactate levels after normal vaginal and elective cesarean delivery: The role of a longer active second stage most significant in high levels after vaginal delivery.

To evaluate umbilical arterial lactate concentrations after spontaneous vaginal delivery and after elective Cesarean delivery, and to study the simultaneous effects of maternal and obstetric variables in high lactate levels in vaginally delivered healthy term singletons. The birth register study included information about the umbilical artery lactate values and clinical perinatal data from 7723 women and their singleton newborns (7301 spontaneous vaginal and 422 elective cesareans) from Kuopio University Hospital, Finland. High lactate levels were evaluated more extensively among healthy term neonates (N = 6541), to evaluate high levels after normal vaginal labors. The mean lactate level was significantly lower after elective cesarean compared to vaginal delivery (2.42 [0.94] vs. 3.56 [1.62] mmol/l; p < 0.0001). Consequently, the 90th percentile limit values were 3.60 and 5.80 mmol/L. Among healthy term newborns born vaginally, higher lactate values (≥5.80 mmol/L) were independently associated with a longer duration of the active second stage of labor (ORs 1.91-10.97) and duration of ruptured fetal membranes (ORs 1.36-2.46), higher gestational age at birth (ORs 1.41-1.86), null parity (OR 2.17), maternal infection (OR 1.81) and short maternal stature (OR 1.45). We report 90th/95th limits for umbilical arterial lactate values in relation to the various durations of labors for term newborns who are delivered by the vaginal route. Even though the high umbilical lactate levels may indicate serious birth asphyxia, levels after vaginal birth reflect the physiological stress and subclinical transient asphyxia frequently seen in normal vaginal deliveries.

Preoperative arterial lactate and outcome after surgery for type A aortic dissection: The ERTAAD multicenter study

BackgroundAcute type A aortic dissection (TAAD) is associated with significant mortality and morbidity. In this study we evaluated the prognostic significance of preoperative arterial lactate concentration on the outcome after surgery for TAAD. MethodsThe ERTAAD registry included consecutive patients who underwent surgery for acute type A aortic dissection (TAAD) at 18 European centers of cardiac surgery. ResultsData on arterial lactate concentration immediately before surgery were available in 2798 (71.7 %) patients. Preoperative concentration of arterial lactate was an independent predictor of in-hospital mortality (mean, 3.5 ± 3.2 vs 2.1 ± 1.8 mmol/L, adjusted OR 1.181, 95%CI 1.129–1.235). The best cutoff value preoperative arterial lactate concentration was 1.8 mmol/L (in-hospital mortality, 12.0 %, vs. 26.6 %, p < 0.0001). The rates of in-hospital mortality increased along increasing quintiles of arterial lactate and it was 12.1 % in the lowest quintile and 33.6 % in the highest quintile (p < 0.0001). The difference between multivariable models with and without preoperative arterial lactate was statistically significant (p = 0.0002). The NRI was 0.296 (95%CI 0.200–0.391) (p < 0.0001) with −17 % of events correctly reclassified (p = 0.0002) and 46 % of non-events correctly reclassified (p < 0.0001). The IDI was 0.025 (95%CI 0.016–0.034) (p < 0.0001). Six studies from a systematic review plus the present one provided data for a pooled analysis which showed that the mean difference of preoperative arterial lactate between 30-day/in-hospital deaths and survivors was 1.85 mmol/L (95%CI 1.22–2.47, p < 0.0001, I2 64 %). ConclusionsHyperlactatemia significantly increased the risk of mortality after surgery for acute TAAD and should be considered in the clinical assessment of these critically ill patients.

Lactate-Based Difference as a Determinant of Outcomes following Surgery for Type A Acute Aortic Dissection: A Multi-Centre Study.

All patients referred to the three cardiovascular centres between January 2005 and December 2022 were included in the study. The inclusion criteria required the presence of a lesion involving the ascending aorta, symptoms within 7 days of surgery, and referral for primary surgical repair of TAAAD based on recommendations, with consideration for other concomitant major cardiac surgical procedures needed during TAAAD and retrograde extension of TAAAD. We conducted an analysis of both continuous and categorical variables and utilised predictive mean matching to fill in missing numeric features. For missing binary variables, we used logistic regression to impute values. We specifically targeted early postoperative mortality and employed LASSO regression to minimise potential collinearity of over-fitting variables and variables measured from the same patient. A total of 633 patients were recruited for the study, out of which 449 patients had complete preoperative arterial lactate data. The average age of the patients was 64 years, and 304 patients were male (67.6%). The crude early postoperative mortality rate was 24.5% (110 out of 449 patients). The mortality rate did not show any significant difference when comparing conservative and extensive surgeries. However, malperfusion had a significant impact on mortality [48/131 (36.6%) vs. 62/318 (19.5%), p < 0.001]. Preoperative arterial lactates were significantly elevated in patients with malperfusion. The optimal prognostic threshold of arterial lactate for predicting early postoperative mortality in our cohort was ≥2.6 mmol/L. The arterial lactate concentration in patients referred for TAAAD is an independent factor for both operative mortality and postoperative complications. In addition to mortality, patients with an upper arterial lactate cut-off of ≥2.6 mmol/L face significant risks of VA ECMO and the need for dialysis within the first 48 h after surgery. To improve recognition and facilitate rapid transfer and surgical treatment protocol, more diligent efforts are required in the management of malperfusion in TAAAD.

Diuretics depletion improves cardiac output and ventriculo-arterial coupling in congestive ICU patients during hemodynamic de-escalation.

Congestion was shown to hamper organ perfusion, but the exact timing of diuretic initiation during hemodynamic de-escalation in shock is unclear. The aim of this study was to describe the hemodynamic effects of diuretic initiation in the stabilized shock. We performed a monocentric, retrospective analysis, in a cardiovascular medico-surgical ICU. We included consecutive resuscitated adult patients, for whom the clinician decided to introduce loop diuretic treatment for clinical signs of fluid overload. The patients were hemodynamically evaluated at the moment of diuretic introduction and 24h later. Seventy ICU patients were included in this study, with a median duration of ICU stay before diuretic initiation of 2 [1-3]days. 51(73%) patients were classified as congestive (central venous pressure > 12 mmHg). After treatment, the cardiac index increased towards normal values in the congestive group (2.7 ± 0.8L min- 1m- 2 from 2.5 ± 0.8L min- 1m- 2, p = 0.042), but not in the non-congestive group (2.7 ± 0.7L min- 1m- 2 from baseline 2.7 ± 0.8L min- 1m- 2, p = 0.968). A decrease in arterial lactate concentrations was observed in the congestive group (2.1 ± 2 mmol L- 1 vs. 1.3 ± 0.6 mmol L- 1, p < 0.001). The diuretic therapy was associated with an improvement of ventriculo-arterial coupling comparing with baseline values in the congestive group (1.69 ± 1 vs. 1.92 ± 1.5, p = 0.03). The norepinephrine use decreased in congestive patients (p = 0.021), but not in the non-congestive group (p = 0.467). The initiation of diuretics in ICU congestive patients with stabilized shock was associated with improvement of cardiac index, ventriculo-arterial coupling, and tissue perfusion parameter. These effects were not observed in non-congestive patients.

Hypertonic sodium lactate infusion reduces vasopressor requirements and biomarkers of brain and cardiac injury after experimental cardiac arrest

IntroductionPrognosis after resuscitation from cardiac arrest (CA) remains poor, with high morbidity and mortality as a result of extensive cardiac and brain injury and lack of effective treatments. Hypertonic sodium lactate (HSL) may be beneficial after CA by buffering severe metabolic acidosis, increasing brain perfusion and cardiac performance, reducing cerebral swelling, and serving as an alternative energetic cellular substrate. The aim of this study was to test the effects of HSL infusion on brain and cardiac injury in an experimental model of CA.MethodsAfter a 10-min electrically induced CA followed by 5 min of cardiopulmonary resuscitation maneuvers, adult swine (n = 35) were randomly assigned to receive either balanced crystalloid (controls, n = 11) or HSL infusion started during cardiopulmonary resuscitation (CPR, Intra-arrest, n = 12) or after return of spontaneous circulation (Post-ROSC, n = 11) for the subsequent 12 h. In all animals, extensive multimodal neurological and cardiovascular monitoring was implemented. All animals were treated with targeted temperature management at 34 °C.ResultsThirty-four of the 35 (97.1%) animals achieved ROSC; one animal in the Intra-arrest group died before completing the observation period. Arterial pH, lactate and sodium concentrations, and plasma osmolarity were higher in HSL-treated animals than in controls (p < 0.001), whereas potassium concentrations were lower (p = 0.004). Intra-arrest and Post-ROSC HSL infusion improved hemodynamic status compared to controls, as shown by reduced vasopressor requirements to maintain a mean arterial pressure target > 65 mmHg (p = 0.005 for interaction; p = 0.01 for groups). Moreover, plasma troponin I and glial fibrillary acid protein (GFAP) concentrations were lower in HSL-treated groups at several time-points than in controls.ConclusionsIn this experimental CA model, HSL infusion was associated with reduced vasopressor requirements and decreased plasma concentrations of measured biomarkers of cardiac and cerebral injury.

A randomized porcine study of hemorrhagic shock comparing end-tidal carbon dioxide targeted and proximal systolic blood pressure targeted partial resuscitative endovascular balloon occlusion of the aorta in the mitigation of metabolic injury

BackgroundThe definition of partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is not yet determined and clinical markers of the degree of occlusion, metabolic effects and end-organ injury that are clinically monitored in real time are lacking. The aim of the study was to test the hypothesis that end-tidal carbon dioxide (ETCO2) targeted pREBOA causes less metabolic disturbance compared to proximal systolic blood pressure (SBP) targeted pREBOA in a porcine model of hemorrhagic shock.Materials and methodsTwenty anesthetized pigs (26–35 kg) were randomized to 45 min of either ETCO2 targeted pREBOA (pREBOAETCO2, ETCO2 90–110% of values before start of occlusion, n = 10) or proximal SBP targeted pREBOA (pREBOASBP, SBP 80–100 mmHg, n = 10), during controlled grade IV hemorrhagic shock. Autotransfusion and reperfusion over 3 h followed. Hemodynamic and respiratory parameters, blood samples and jejunal specimens were analyzed.ResultsETCO2 was significantly higher in the pREBOAETCO2 group during the occlusion compared to the pREBOASBP group, whereas SBP, femoral arterial mean pressure and abdominal aortic blood flow were similar. During reperfusion, arterial and mesenteric lactate, plasma creatinine and plasma troponin concentrations were higher in the pREBOASBP group.ConclusionsIn a porcine model of hemorrhagic shock, ETCO2 targeted pREBOA caused less metabolic disturbance and end-organ damage compared to proximal SBP targeted pREBOA, with no disadvantageous hemodynamic impact. End-tidal CO2 should be investigated in clinical studies as a complementary clinical tool for mitigating ischemic–reperfusion injury when using pREBOA.

Arterial Lactate Concentration at the End of Liver Transplantation is Independently Associated With One-Year Mortality

Liver transplant patients who develop hyperlactatemia are at increased risk of postoperative morbidity and short-term mortality, but there are few data on longer-term outcomes. We therefore investigated if arterial lactate concentration obtained immediately after surgery, at the time of admission to the intensive care unit (ICU), was associated with 1-year mortality. In this retrospective cohort study, all patients who underwent liver transplant surgery from a deceased donor between September 2013 and December 2019 were screened for inclusion. Patients who underwent combined transplantation surgery and those with a history of previous liver transplantation (ie, redo surgery) were not included. Logistic regression modeling included univariate and multivariate analyses. Receiver operating characteristic curves and areas under the curves were calculated. Lactate thresholds and association with outcome were analyzed for specificity, sensitivity, and Youden's index. Of 226 patients included, 18.4% died within 1 year of liver transplantation. Immediate postoperative lactate concentration was independently associated with 1-year mortality with an adjusted odds ratio of 1.35 (95% CI 1.16-1.59; P < .001) per mmol/L increase in lactate and an area under the curve of 0.80 (95% CI 0.72-0.87; P < .001). A lactate concentration of 2.25 mmol/L (cutoff determined using Youden's index) was associated with increased 1-year mortality with a sensitivity of 0.71 and a specificity of 0.72. Increased arterial lactate concentration on admission to the intensive care unit immediately after orthotopic liver transplantation is independently associated with increased 1-year mortality.

The combination of arterial lactate level with GCS-pupils score to evaluate short term prognosis in traumatic brain injury: a retrospective study

BackgroundThe aim of the study was to determine whether the combination of Glasgow Coma Scale (GCS) and Pupil responses score (GCSP) with arterial lactate level would be an index to predict the short term prognosis in patients with traumatic brain injury (TBI).MethodsA retrospective study was performed enrolling all TBI patients admitted to intensive care unit (ICU) from 2019 to 2020. The demographics, clinical characteristics, and arterial lactate concentration were recorded. The GCSP and arterial blood analysis (ABG) with lactate was tested as soon as the patient was admitted to ICU. The Glasgow Outcome Scale (GOS) after discharge was regarded as the clinical outcome. A new index named GCSP-L was the combination of GCSP and lactate concentration. GCSP-L was the GCSP score (range 1-15) plus the lactate score (range 0-2). The lactate score was defined based on different lactate concentrations. If lactate was below 2 mmol/L, lactate score was 0, which above 5 mmol/L was 2 and between 2 and 5 mmol/L, the score was 1. As the range of GCSP was 1-15, the range of the GCSP-L was 1 to 17. The area under receiver operating characteristic curve (AUC) was calculated to evaluate the predictive ability of GCSP, lactate and GCSP-L. Statistical significance was set when p value < 0.05.ResultsA total of 192 TBI patients were included in the study. Based on GCSP, mild, moderate, and severe TBI were 13.02, 14.06 and 72.92%, respectively. There were 103 (53.65%) patients with the lactate concentration below 2 mmol/L (1.23 ± 0.37 mmol/l), 63 (32.81%) of the range from 2 to 5 (3.04 ± 2.43 mmol/l) and 26 (13.54%) were above 5 mmol/l (7.70 ± 2.43 mmol/l). The AUC was 0.866 (95% CI 0.827-0.904) for GCSP-L, 0.812 (95% CI 0.765-0.858) for GCSP and 0.629 (95% CI 0.570—0.0.688) for lactate. The AUC of GCSP-L was higher than the other two, GCSP and lactate alone.ConclusionsThe combination of GCSP and lactate concentration can be used to predict the short term prognosis in TBI patients.

Fluid balance neutralization secured by hemodynamic monitoring versus protocolized standard of care in critically ill patients requiring continuous renal replacement therapy: study protocol of the GO NEUTRAL randomized controlled trial

BackgroundFluid overload is associated with worse outcome in critically ill patients requiring continuous renal replacement therapy (CRRT). Net ultrafiltration (UFNET) allows precise control of the fluid removal but is frequently ceased due to hemodynamic instability episodes. However, approximately 50% of the hemodynamic instability episodes in ICU patients treated with CRRT are not associated with preload dependence (i.e., are not related to a decrease in cardiac preload), suggesting that volume removal is not responsible for these episodes of hemodynamic impairment. The use of advanced hemodynamic monitoring, comprising continuous cardiac output monitoring to repeatedly assess preload dependency, could allow securing UFNET to allow fluid balance control and prevent fluid overload.MethodsThe GO NEUTRAL trial is a multicenter, open-labeled, randomized, controlled, superiority trial with parallel groups and balanced randomization with a 1:1 ratio. The trial will enroll adult patients with acute circulatory failure treated with vasopressors and severe acute kidney injury requiring CRRT who already have been equipped with a continuous cardiac output monitoring device. After informed consent, patients will be randomized into two groups. The control group will receive protocolized fluid removal with an UFNET rate set to 0–25 ml h−1 between inclusion and H72 of inclusion. The intervention group will be treated with an UFNET rate set on the CRRT of at least 100 ml h−1 between inclusion and H72 of inclusion if hemodynamically tolerated based on a protocolized hemodynamic protocol aiming to adjust UFNET based on cardiac output, arterial lactate concentration, and preload dependence assessment by postural maneuvers, performed regularly during nursing rounds, and in case of a hemodynamic instability episode. The primary outcome of the study will be the cumulative fluid balance between inclusion and H72 of inclusion. Randomization will be generated using random block sizes and stratified based on fluid overload status at inclusion. The main outcome will be analyzed in the modified intention-to-treat population, defined as all alive patients at H72 of inclusion, based on their initial allocation group.DiscussionWe present in the present protocol all study procedures in regard to the achievement of the GO NEUTRAL trial, to prevent biased analysis of trial outcomes and improve the transparency of the trial result report. Enrollment of patients in the GO NEUTRAL trial has started on June 31, 2021, and is ongoing.Trial registrationClinicalTrials.gov NCT04801784. Registered on March 12, 2021, before the start of inclusion.

Lactate during ex-situ heart perfusion does not predict the requirement for mechanical circulatory support following donation after circulatory death (DCD) heart transplants.

Ex-situ heart perfusion (ESHP) is commonly used for the reanimation and preservation of hearts following donation after circulatory determined death (DCD). The only commercially available existing ESHP device promotes perfusate lactate levels for assessment of heart viability. The reliability of this marker is yet to be confirmed for DCD heart transplantation. This is a single center, retrospective study examining DCD heart transplants from March 1, 2015 to June 30, 2020. Recipients were divided into 2 groups dependent upon their requirement for or absence of mechanical circulatory support post-transplant. Lactate profiles obtained during ESHP were analyzed. Hearts were procured using the direct procurement and perfusion (DPP) method. Fifty-one DCD heart transplant recipients were studied, of which 20 (39%) were dependent on mechanical circulatory support (MCS) following transplantation, (2% Ventricular Assist Device (VAD), 16% Extra Corporeal Membrane Oxygenation (ECMO) and 21% Intra-aortic balloon pumps (IABP). There was no difference in arterial lactate profiles on ESHP at any time point for those dependent upon MCS support (MCS) and those that were not (no MCS) post-transplant. After 3 hours of ESHP, the arterial lactate was >5mmol/L in 80% upon MCS vs 62% no MCS, p=.30. There was also no difference in ESHP rising arterial lactate concentrations, (15% MCS vs 13% non MCS, p=1.00). For DCD hearts transplants retrieved using the DPP technique, lactate profiles do not seem to be a reliable predictor of mechanical circulatory support requirement post-transplant.

Microcirculation assessment of dexmedetomidine constant rate infusion during anesthesia of dogs with sepsis from pyometra: a randomized clinical study

ObjectiveTo compare dexmedetomidine and fentanyl constant rate infusions in anesthetic protocols for septic dogs with pyometra, using microcirculatory, hemodynamic and metabolic variables. Study designRandomized clinical study. AnimalsA total of 33 dogs with pyometra with two or more systemic inflammatory response syndrome variables undergoing ovariohysterectomy. MethodsDogs were randomized into two groups: group DG, dexmedetomidine (3 μg kg–1 hour–1; 17 dogs) and group FG, fentanyl (5 μg kg–1 hour–1; 16 dogs) infused during isoflurane anesthesia and mechanical ventilation. Microcirculation flow index (MFI), total vessel density and De Backer score were assessed using orthogonal polarization spectral imaging at the sublingual site. Heart rate, invasive blood pressure, temperature, arterial blood gas analysis and lactate concentration were obtained at various time points. Variables were recorded at baseline (BL), immediately before (T0), 30 (T30) and 60 (T60) minutes after infusion, and 60 minutes after surgery. Data were analyzed using the Shapiro-Wilk test. To compare variables between groups, the unpaired Student t test was used. Comparison between evaluation time points was performed with two-way anova for repeated measures. Where statistical significance was detected, the Bonferroni post hoc test was used. ResultsMFI was significantly higher in group FG at T30. Mean arterial pressure at T30 was higher in group DG (89 ± 15 mmHg) than in group FG (72 ± 13 mmHg). Lactate concentrations were not significantly different between groups at each time point. Both groups had similar clinical outcomes (mortality, extubation time and occurrence of hypotension and bradyarrhythmias). Conclusions and clinical relevanceDexmedetomidine (3 μg kg–1 hour–1) without a loading dose can be included in the maintenance of anesthesia in dogs with pyometra and sepsis without compromising microcirculation and hemodynamic values when compared with fentanyl (5 μg kg–1 hour–1).

A clinical study of the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections

BackgroundResuscitative endovascular balloon occlusion of the aorta (REBOA) is a key procedure in sacral and pelvic tumor resection that provides hemorrhage control. However, few studies have been performed to capture the effects of REBOA in a nonshock condition and provide a detailed description of the changes occurring with prolonged occlusion time. This study aimed to examine the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections following different periods of REBOA.MethodsIn total, 121 patients who underwent surgical tumor resections of the pelvis and/or the sacrum with the use of aortic balloon occlusion were prospectively enrolled from October 2020 to December 2021. All cases were divided into Group A (occlusion time ≤ 60 min, n = 57) and Group B (occlusion time ≥ 90 min, n = 64). Physiologic parameters were continuously recorded, and laboratory specimens were obtained at regular intervals.ResultsBalloon inflation resulted in a significant increase in SBP from 106 to 120 mmHg and decreased to 96 mmHg immediately following balloon deflation. With the application of REBOA, the median blood loss was only 1200 ml (range, 400–7900). When deflating the REBOA, the arterial pH was lower than baseline (7.36 vs. 7.41, p < 0.01), the arterial lactate concentration increased from 0.9 to 1.4 mmol/L (p < 0.01), serum potassium measurements increased from 3.99 to 4.12 mmol/L, serum calcium measurements decreased from 2.31 to 2.04 mmol/L, and blood creatinine decreased from 64 to 60 µmol/L. The operating time of Group B was longer than that of patients in Group A, and the patients in Group B needed more blood units to be transfused. Although laboratory measurements, including pH, potassium, calcium, and blood creatinine, were at the same level in two groups comparison, the lactate was significantly higher in Group B after deflation (p = 0.01).ConclusionsThe results of this study showed that acceptable hemodynamic and metabolic stability can be attained when the occlusion time of REBOA is more than 90 min, although the long duration of occlusion caused relatively higher lactate levels.

High Arterial Lactate Levels after Hepatic Resection Are Associated with Low Oxygen Delivery and Predict Severe Postoperative Complications.

High End-Surgery Arterial Lactate Concentration (ES-ALC) predicts poor outcome after hepatectomy. The aim of this study was to identify intraoperative hemodynamic parameters predicting high ES-ALC during elective liver resection. Patients who underwent liver resection between 2017 and 2018, under FloTrac/EV1000TM hemodynamic monitoring, were included. The ES-ALC cutoff best predicting severe postoperative complications was identified. Association between high ES-ALC and preoperative and intraoperative variables was assessed. 108 patients were included; 90-day mortality was 0.9% and severe morbidity 14.8%. ES-ALC cutoff best discriminating severe complications was 5.05 mmol/L. Patients with ES-ALC > 5.0 mmol/L had a relative risk of severe complications of 2.8% (p = 0.004). High ES-ALC patients had longer surgery and ischemia duration, larger blood losses and higher requirements of fluids and blood transfusions. During surgery, hemoglobin concentration and oxygen delivery (DO2) decreased more significantly in patients with high ES-ALC, although they had similar values of stroke volume and cardiac output to those of other patients. At multivariate analysis, surgery duration and lowest recorded DO2 value were the strongest predictors of high ES-ALC. ES-ALC > 5.0 mmol/L in elective liver resection predicts postoperative morbidity and is essentially driven by the impaired DO2. Timely correction of blood losses might prevent the ES-ALC increase.

Automated aortic endovascular balloon volume titration prevents re-arrest immediately after return of spontaneous circulation in a swine model of nontraumatic cardiac arrest

ObjectivesEndovascular aortic occlusion as an adjunct to cardiopulmonary resuscitation (CPR) for non-traumatic cardiac arrest is gaining interest. In a recent clinical trial, return of spontaneous circulation (ROSC) was achieved despite prolonged no-flow times. However, 66% of patients re-arrested upon balloon deflation. We aimed to determine if automated titration of endovascular balloon volume following ROSC can augment diastolic blood pressure (DBP) to prevent re-arrest. MethodsTwenty swine were anesthetized and placed into ventricular fibrillation (VF). Following 7 minutes of no-flow VF and 5 minutes of mechanical CPR, animals were subjected to complete aortic occlusion to adjunct CPR. Upon ROSC, the balloon was either deflated steadily over 5 minutes (control) or underwent automated, dynamic adjustments to maintain a DBP of 60 mmHg (Endovascular Variable Aortic Control, EVAC). ResultsROSC was obtained in ten animals (5 EVAC, 5 REBOA). Sixty percent (3/5) of control animals rearrested while none of the EVAC animals rearrested (p = 0.038). Animals in the EVAC group spent a significantly higher proportion of the post-ROSC period with a DBP > 60 mmHg [median (IQR)] [control 79.7 (72.5–86.0)%; EVAC 97.7 (90.8–99.7)%, p = 0.047]. The EVAC group had a statistically significant reduction in arterial lactate concentration [7.98 (7.4–8.16) mmol/L] compared to control [9.93 (8.86–10.45) mmol/L, p = 0.047]. There were no statistical differences between the two groups in the amount of adrenaline (epinephrine) required. ConclusionIn our swine model of cardiac arrest, automated aortic endovascular balloon titration improved DBP and prevented re-arrest in the first 20 minutes after ROSC.

Novel Portable Hypothermic Cardiac Preservation Device Extends Cardiac Viability and Function Beyond the Standard of Care Using Isolated Porcine Hearts

<h3>Purpose</h3> The standard of care: cold static storage (CSS), limits the time a heart can be preserved to 4-6 hours. Machine perfusion preservation has been shown to improve organ viability. However, current machine perfusion technology is complex and requires the use of blood or blood products. The purpose of this study was to test the efficacy of a portable hypothermic oxygenated and acellular perfusion machine device, in preserving cardiac viability and function in comparison to CSS for 4 hours at different perfusion times using an isolated heart porcine model. <h3>Methods</h3> Isolated porcine hearts (N=17) were recovered under anesthesia and by inducing cardiac arrest through cardioplegia administration. Experimental hearts were perfused using a novel cardiac preservation device with an acellular perfusate at 4-8°C for 4 hours(n=3), 8 hours(n=4), and 24 hours(n=3). In addition, 3 hearts were perfused for 2 hours and then kept inside the perfusor at 4-8°C for an additional 4 hours without perfusion (extended mode), to determine efficacy during inoperable conditions. Controls (n=4) were hearts kept in CSS for 4 hours. Hourly flow, pressure, temperature, and blood gas measurements were taken from perfused hearts. After preservation, the hearts were placed in a Langendorff for functional recovery determined by +/- dP/dT and maximum pressure. Biopsy samples were taken before and at the end of either preservation method for histological and gene expression analyses. <h3>Results</h3> Control hearts weight gain (%) was -3.4 ± 4.9 and perfused hearts was 1.52 ± 7.6. Venous and arterial lactate concentrations were less than 2.5 mmol/L across all experiments. Perfused hearts at 4 hours, 8 hours, and extended mode had significantly increased contractility (p<0.05) than CSS demonstrated by +dP/dT and peak pressure. Gene expression showed a significant reduction (p<0.005) of inflammation (IL-6, IL-8, TNFα) and cell death markers (p53,cTnI) in perfused hearts compared to control hearts. Furthermore, histological assessment confirmed greater myocardium damage in CSS hearts. <h3>Conclusion</h3> This novel cardiac preservation device enhances cardiac viability and function compared to CSS. Furthermore, it allows for 4 hours of CSS after 2 hours of perfusion in case of cessation of perfusion. Animal transplant studies will be conducted to verify these results.

Comment on: Early postoperative arterial lactate concentrations to stratify risk of post-hepatectomy liver failure.

Comment on: Early postoperative arterial lactate concentrations to stratify risk of post-hepatectomy liver failure.

Effects of intravenous ethyl pyruvate on cardiopulmonary variables and quality of recovery from anesthesia in horses

ObjectiveTo determine the effects of intravenous ethyl pyruvate, an anti-inflammatory with putative benefits in horses with endotoxemia, on cardiopulmonary variables during anesthesia and the quality of anesthetic recovery. Study designRandomized, crossover, blinded experimental design. AnimalsA total of six healthy Standardbred geldings, aged 13 ± 3 years and weighing 507 ± 66 kg (mean ± standard deviation). MethodsHorses were anesthetized for approximately 90 minutes on two occasions with a minimum of 2 weeks apart using xylazine for sedation, ketamine and diazepam for induction, and isoflurane in oxygen for maintenance. Lactated Ringer’s solution (LRS; 10 mL kg–1 hour–1) was administered during anesthesia. Treatments were randomized and administered starting approximately 30 minutes after induction of anesthesia and infused over 60 minutes: LRS (1 L) or ethyl pyruvate (150 mg kg–1 in 1 L LRS). Invasive arterial pressures, heart rate, respiratory rate and end-tidal carbon dioxide tensions were recorded every 5 minutes for the duration of anesthesia. Arterial blood gases, glucose and lactate concentrations were measured every 20 minutes. Anesthetic recovery was video recorded, stored, and subsequently rated by two individuals blinded to treatments. Total recovery time, time to extubation, number of attempts and time to sternal recumbency, number of attempts to stand and time to stand were recorded. Quality of recovery was analyzed. Data between treatments and within a treatment were assessed using two-way repeated-measures anova and a Pearson correlation coefficient, significant at p < 0.05. ResultsAll horses completed the study. No significant differences were detected between the ethyl pyruvate and LRS treatments for either the cardiopulmonary variables or quality of recovery from anesthesia. Conclusions and clinical relevanceThe results suggest that intravenous ethyl pyruvate can be administered to healthy anesthetized horses with minimal impact on the cardiopulmonary variables studied or the quality of recovery from anesthesia.