Influence of compliance to antithrombotic agents on perioperative morbidity and mortality.

For patients on antithrombotic medication, the outcome of a planned surgery depends on the adjustment of their daily treatment. This study aimed to assess the impact of non-compliance to published recommendations about antithrombotic agents, specifically those provided by the Groupement d'Intérêt pour l'hémostase Peri-opératoire (GIHP), on patient morbidity and mortality.A prospective cohort observational monocentric study was conducted over a 7-month period in 2019 in an academic hospital. The study included patients on antithrombotic agents scheduled for elective surgery, excluding cardiac surgery. The primary endpoints were morbidity and mortality at 1 month according to GIHP guidelines compliance. Blood loss during surgery and length of hospital stay were secondary endpoints.Among the 589 patients included in the study, 87 complications were recorded, resulting in a morbidity rate of 14.8%. Thirty-six patients experienced hemorrhagic events, leading to 8 deaths, while 33 patients suffered from ischemic events, resulting in 3 deaths. Additionally, 18 patients died from causes unrelated to hemorrhage or ischemia. Compliance with GIHP guidelines was observed in 62% of patients. Statistical analysis did not reveal a significant association between adherence to guidelines and morbidity (p value = 0.923), nor between adherence and 1-month survival (p value = 0.698). Similarly, no statistically significant relationships were found between compliance and intraoperative bleeding volume (p value = 0.087), postoperative bleeding (p value = 0.460), or length of hospital stay (p value = 0.339).This study did not identify any substantial associations between non-strict adherence to GIHP recommendations and patient outcomes, including morbidity, mortality, and bleeding. However, it is important to interpret these findings with caution, considering the study's limitations and the need for further research in this area.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Increased arterial lactate concentration on admission to the intensive care unit immediately after orthotopic liver transplantation is independently associated with increased 1-year mortality.

Perioperative antimicrobial prophylaxis in patients undergoing pancreatoduodenectomy: retrospective analysis of bacteriological profile and susceptibility.

BACKGROUND: Pancreatic tumours are frequently associated with obstructive jaundice requiring preoperative biliary drainage (PBD) before pancreatoduodenectomy (PD), exposing patients to infectious complications. This study aims to compare postoperative complications after PD with or without PBD and to analyse bile bacteriology and antibiotic susceptibility. METHODS: All patients undergoing PD between 2014 and 2019 were retrospectively evaluated, and postoperative outcomes were compared according to PBD use. Prophylactic narrow-spectrum antibiotic therapy was given for 24 h, then adapted according to bacteriologic profile. Intraoperative bile cultures and antibiograms were collected. RESULTS: Among 164 patients with intraoperative bile culture during PD (75 PBD+, 89 PBD-), an infected bile was observed in 95% and 70% of PBD + and PBD- groups, respectively (p < 0.001). Postoperative mortality and severe morbidity including infectious complications were similar between groups (5% and 15%). The median duration of antibiotherapy was longer in PBD + compared to PBD- groups (9 vs. 2 days, p = 0.009). Malignant indication and PBD were associated with bile contamination using univariate analysis, and PBD was significantly relevant at multivariate analysis. Most common pathogens identified in bile cultures were Escherichia coli, Klebsiella spp. and Enterobacter spp. Overall antibiotic susceptibility to commonly used antibiotics was decreased, including those used in our local guidelines. CONCLUSIONS: PBD exposes nearly 100% of patients undergoing PD to bile infection and an increased duration of postoperative antimicrobial therapy, without increasing infectious complications in this study. Adaptation of antimicrobial prophylaxis should be further evaluated according to performance of PBD and local epidemiology, in order to avoid overuse of antibiotics.

Impact of conventional vs. goal-directed fluid therapy on urethral tissue perfusion in patients undergoing liver surgery: A pilot randomised controlled trial.

BACKGROUND: Although fluid administration is a key strategy to optimise haemodynamic status and tissue perfusion, optimal fluid administration during liver surgery remains controversial. OBJECTIVE: To test the hypothesis that a goal-directed fluid therapy (GDFT) strategy, when compared with a conventional fluid strategy, would better optimise systemic blood flow and lead to improved urethral tissue perfusion (a new variable to assess peripheral blood flow), without increasing blood loss. DESIGN: Single-centre prospective randomised controlled superiority study. SETTING: Erasme Hospital. PATIENTS: Patients undergoing liver surgery. INTERVENTION: Forty patients were randomised into two groups: all received a basal crystalloid infusion (maximum 2 ml kg-1 h-1). In the conventional fluid group, the goal was to maintain central venous pressure (CVP) as low as possible during the dissection phase by giving minimal additional fluid, while in the posttransection phase, anaesthetists were free to compensate for any presumed fluid deficit. In the GDFT group, patients received in addition to the basal infusion, multiple minifluid challenges of crystalloid to maintain stroke volume (SV) variation less than 13%. Noradrenaline infusion was titrated to keep mean arterial pressure more than 65 mmHg in all patients. MAIN OUTCOME MEASURE: The mean intra-operative urethral perfusion index. RESULTS: The mean urethral perfusion index was significantly higher in the GDFT group than in the conventional fluid group (8.70 [5.72 to 13.10] vs. 6.05 [4.95 to 8.75], P = 0.046). SV index (ml m-2) and cardiac index (l min-1 m-2) were higher in the GDFT group (48 ±â€Š9 vs. 33 ±â€Š7 and 3.5 ±â€Š0.7 vs. 2.4 ±â€Š0.4, respectively; P < 0.001). Although CVP was higher in the GDFT group (9.3 ±â€Š2.5 vs. 6.5 ±â€Š2.9 mmHg; P = 0.003), intra-operative blood loss was not significantly different in the two groups. CONCLUSION: In patients undergoing liver surgery, a GDFT strategy resulted in a higher mean urethral perfusion index than did a conventional fluid strategy and did not increase blood loss despite higher CVP. TRIAL REGISTRATION: NCT04092608.

Mild increases in plasma creatinine after intermediate to high-risk abdominal surgery are associated with long-term renal injury.

BACKGROUND: The potential relationship between a mild acute kidney injury (AKI) observed in the immediate postoperative period after major surgery and its effect on long term renal function remains poorly defined. According to the "Kidney Disease: Improving Global Outcomes" (KDIGO) classification, a mild injury corresponds to a KIDIGO stage 1, characterized by an increase in creatinine of at least 0.3 mg/dl within a 48-h window or 1.5 to 1.9 times the baseline level within the first week post-surgery. We tested the hypothesis that patients who underwent intermediate-to high-risk abdominal surgery and developed mild AKI in the following days would be at an increased risk of long-term renal injury compared to patients with no postoperative AKI. METHODS: All consecutive adult patients with a plasma creatinine value ≤1.5 mg/dl who underwent intermediate-to high-risk abdominal surgery between 2014 and 2019 and who had at least three recorded creatinine measurements (before surgery, during the first seven postoperative days, and at long-term follow up [6 months-2 years]) were included. AKI was defined using a "modified" (without urine output criteria) KDIGO classification as mild (stage 1 characterised by an increase in creatinine of > 0.3 mg/dl within 48-h or 1.5-1.9 times baseline) or moderate-to-severe (stage 2-3 characterised by increase in creatinine 2 to 3 times baseline or to ≥4.0 mg/dl). The exposure (postoperative kidney injury) and outcome (long-term renal injury) were defined and staged according to the same KDIGO initiative criteria. Development of long-term renal injury was compared in patients with and without postoperative AKI. RESULTS: Among the 815 patients included, 109 (13%) had postoperative AKI (81 mild and 28 moderate-to-severe). The median long-term follow-up was 360, 354 and 353 days for the three groups respectively (P = 0.2). Patients who developed mild AKI had a higher risk of long-term renal injury than those who did not (odds ratio 3.1 [95%CI 1.7-5.5]; p < 0.001). In multivariable analysis, mild postoperative AKI was independently associated with an increased risk of developing long-term renal injury (adjusted odds ratio 4.5 [95%CI 1.8-11.4]; p = 0.002). CONCLUSIONS: Mild AKI after intermediate-to high-risk abdominal surgery is associated with a higher risk of long-term renal injury 1 y after surgery.

Intraoperative hypotension during liver transplant surgery is associated with postoperative acute kidney injury: a historical cohort study.

BACKGROUND: Acute kidney injury (AKI) occurs frequently after liver transplant surgery and is associated with significant morbidity and mortality. While the impact of intraoperative hypotension (IOH) on postoperative AKI has been well demonstrated in patients undergoing a wide variety of non-cardiac surgeries, it remains poorly studied in liver transplant surgery. We tested the hypothesis that IOH is associated with AKI following liver transplant surgery. METHODS: This historical cohort study included all patients who underwent liver transplant surgery between 2014 and 2019 except those with a preoperative creatinine > 1.5 mg/dl and/or who had combined transplantation surgery. IOH was defined as any mean arterial pressure (MAP) < 65 mmHg and was classified according to the percentage of case time during which the MAP was < 65 mmHg into three groups, based on the interquartile range of the study cohort: "short" (Quartile 1, < 8.6% of case time), "intermediate" (Quartiles 2-3, 8.6-39.5%) and "long" (Quartile 4, > 39.5%) duration. AKI stages were classified according to a "modified" "Kidney Disease: Improving Global Outcomes" (KDIGO) criteria. Logistic regression modelling was conducted to assess the association between IOH and postoperative AKI. The model was run both as a univariate and with multiple perioperative covariates to test for robustness to confounders. RESULTS: Of the 205 patients who met our inclusion criteria, 117 (57.1%) developed AKI. Fifty-two (25%), 102 (50%) and 51 (25%) patients had short, intermediate and long duration of IOH respectively. In multivariate analysis, IOH was independently associated with an increased risk of AKI (adjusted odds ratio [OR] 1.05; 95%CI 1.02-1.09; P < 0.001). Compared to "short duration" of IOH, "intermediate duration" was associated with a 10-fold increased risk of developing AKI (OR 9.7; 95%CI 4.1-22.7; P < 0.001). "Long duration" was associated with an even greater risk of AKI compared to "short duration" (OR 34.6; 95%CI 11.5-108.6; P < 0.001). CONCLUSIONS: Intraoperative hypotension is independently associated with the development of AKI after liver transplant surgery. The longer the MAP is < 65 mmHg, the higher the risk the patient will develop AKI in the immediate postoperative period, and the greater the likely severity. Anesthesiologists and surgeons must therefore make every effort to avoid IOH during surgery.

Intravenous lidocaine to prevent endothelial dysfunction after major abdominal surgery: a randomized controlled pilot trial.

BACKGROUND: Major abdominal surgery is associated with endothelial glycocalyx disruption. The anti-inflammatory effects of lidocaine were recently associated with endothelial barrier protection. METHODS: This was a single-centre, parallel group, randomized, controlled, double blind, pilot trial. Forty adult patients scheduled for major abdominal surgery were included between December 2016 and March 2017 in the setting of a University Hospital in Brussels (Belgium); reasons for non-inclusion were planned liver resection and conditions associated to increased risk of local anesthetics systemic toxicity. Patients were randomized to receive either lidocaine by continuous intravenous administration or an equivalent volume of 0.9% saline. The primary endpoint was the postoperative syndecan-1 concentration (difference between groups). Near-infrared spectroscopy of the thenar eminence in association with the vascular occlusion test, and contemporary analysis of flow-mediated dilation of the brachial artery were the secondary outcomes, along with haemodynamic data. Blood samples and data were collected before surgery (T0), and at 1-3 h (T1) and 24 h (T2) post-surgery. RESULTS: Syndecan-1 concentration increased significantly post-surgery (P < 0.001), but without any difference between groups. The near-infrared spectroscopy-derived and flow-mediated dilation-derived variables showed minor changes unrelated to group assignment. Compared with the placebo group, the intervention group had a significantly lower peri-operative mean arterial pressure and cardiac index, despite equally conducted goal-directed haemodynamic management. Postoperative lactate concentrations were similar between groups. CONCLUSIONS: Lidocaine failed to have any effect on endothelial function. Since in comparisons to other types of clinical situations, syndecan-1 was only slightly upregulated, endothelial dysfunction after major abdominal surgery might be overestimated. TRIAL REGISTRATION: « ISRCTN Registry ¼ identifier: ISRCTN63417725. Date: 15/06/2020. Retrospectively registered.

Management of antiplatelet therapy for non-elective invasive procedures or bleeding complications: Proposals from the French Working Group on Perioperative Haemostasis (GIHP) and the French Study Group on Thrombosis and Haemostasis (GFHT), in collaboration with the French Society for Anaesthesia and Intensive Care (SFAR).

The French Working Group on Perioperative Haemostasis (GIHP) and the French Study Group on Haemostasis and Thrombosis (GFHT), in collaboration with the French Society for Anaesthesia and Intensive Care (SFAR), drafted up-to-date proposals on the management of antiplatelet therapy for non-elective invasive procedures or bleeding complications. The proposals were discussed and validated by a vote; all proposals could be assigned with a high strength. Management of oral antiplatelet agents in emergency settings requires knowledge of their pharmacokinetic and pharmacodynamic parameters, evaluation of the degree of alteration of haemostatic competence and the associated bleeding risk. Platelet function testing may be considered. When antiplatelet agent-induced bleeding risk may worsen the prognosis, measures should be taken to neutralize antiplatelet therapy, by considering not only the efficacy of available means (which can be limited for prasugrel and even more for ticagrelor), but also the risks that these means expose the patient to. The measures include platelet transfusion at the appropriate dose and haemostatic agents (tranexamic acid; recombinant activated factor VII for ticagrelor). When possible, postponing non-elective invasive procedures at least for a few hours until the elimination of the active compound (which could compromise the effect of transfused platelets) or, if possible, for a few days (reduction of the effect of antiplatelet agents) should be considered.

Position of the French Working Group on Perioperative Haemostasis (GIHP) on viscoelastic tests: What role for which indication in bleeding situations?

PURPOSE: Viscoelastic tests (VETs), thromboelastography (TEG®) and thromboelastometry (ROTEM®) are global tests of coagulation performed on whole blood. They evaluate the mechanical strength of a clot as it builds and develops after coagulation itself. The time required to obtain haemostasis results remains a major problem for clinicians dealing with bleeding, although some teams have developed a rapid laboratory response strategy. Indeed, the value of rapid point-of-care diagnostic devices such as VETs has increased over the years. However, VETs are not standardised and there are few recommendations from the learned societies regarding their use. In 2014, the recommendations of the International Society of Thrombosis and Haemostasis (ISTH) only concerned haemophilia. The French Working Group on Perioperative haemostasis (GIHP) therefore proposes to summarise knowledge on the clinical use of these techniques in the setting of emergency and perioperative medicine. METHODS: A review of the literature. PRINCIPAL FINDINGS: The role of the VETs seems established in the management of severe trauma and in cardiac surgery, both adult and paediatric. In other situations, their role remains to be defined: hepatic transplantation, postpartum haemorrhage, and non-cardiac surgery. They must be part of the global management of haemostasis based on algorithms defined in each centre and for each population of patients. Their position at the bedside or in the laboratory is a matter of discussion between clinicians and biologists. CONCLUSION: VETs must be included in algorithms. In consultation with the biology laboratory, these devices should be situated according to the way each centre functions.

Practical impact of a decision support for goal-directed fluid therapy on protocol adherence: a clinical implementation study in patients undergoing major abdominal surgery.

The purpose of this study was to assess the effects of using a real time clinical decision-support system, "Assisted Fluid Management" (AFM), to guide goal-directed fluid therapy (GDFT) during major abdominal surgery. We compared a group of patients managed using the AFM system with a historical cohort of patients (control group) who had been managed using a manual GDFT strategy. Adherence to the protocol was defined as the relative intraoperative time spent with a stroke volume variation (SVV) < 13%. We hypothesised that patients in the AFM group would have more time during surgery with a SVV < 13% compared to the control group. All patients had a radial arterial line connected to a pulse contour analysis monitor and received a 2 ml/kg/h maintenance crystalloid infusion. Additional 250 ml crystalloid boluses were administered whenever measured SVV ≥ 13% in the control group, and when the software suggested a fluid bolus in the AFM group. We compared 46 AFM-guided patients to 38 controls. Patients in the AFM group spent significantly more time during surgery with a SVV < 13% compared to the control group (median 92% [82, 96] vs. 76% [54, 86]; P < 0.0005), and received less fluid overall (1775 ml [1225, 2425] vs. 2350 ml [1825, 3250]; P = 0.010). The incidence of postoperative complications was comparable in the two groups. Implementation of a decision support system for GDFT guidance resulted in a significantly longer period during surgery with a SVV < 13% with a reduced total amount of fluid administered. Trial registration: Clinical Trials.gov (NCT03141411).

Long-term Impact of Crystalloid versus Colloid Solutions on Renal Function and Disability-free Survival after Major Abdominal Surgery.

BACKGROUND: The authors recently demonstrated that administration of balanced hydroxyethyl starch solution as part of intraoperative goal-directed fluid therapy was associated with better short-term outcomes than administration of a balanced crystalloid solution in patients having major open abdominal surgery. In the present study, a 1-yr follow-up of renal and disability outcomes in these patients was performed. METHODS: All patients enrolled in the earlier study were followed up 1 yr after surgery for renal function and disability using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS). The main outcome measure was the estimated glomerular filtration rate. Other outcomes were serum creatinine, urea, pruritus, and WHODAS score. Groups were compared on a complete-case analysis basis, and modern imputation methods were then used in mixed-model regressions to assess the stability of the findings taking into account the missing data. RESULTS: Of the 160 patients enrolled in the original study, follow-up data were obtained for renal function in 129 and for WHODAS score in 114. There were no statistically significant differences in estimated glomerular filtration rate at 1 yr (ml min 1.73 m): 80 [65 to 92] for crystalloids versus 74 [64 to 94] for colloids; 95% CI [-10 to 7], P = 0.624. However, the WHODAS score (%) was statistically significantly lower in the colloid than in the crystalloid group (2.7 [0 to 12] vs. 7.6 [1.3 to 18]; P = 0.015), and disability-free survival was higher (79% vs. 60%; 95% CI [2 to 39]; P = 0.024). CONCLUSIONS: In patients undergoing major open abdominal surgery, there was no evidence of a statistically significant difference in long-term renal function between a balanced hydroxyethyl starch and a balanced crystalloid solution used as part of intraoperative goal-directed fluid therapy, although there was only limited power to rule out a clinically significant difference. However, disability-free survival was significantly higher in the colloid than in the crystalloid group.

Implementation of closed-loop-assisted intra-operative goal-directed fluid therapy during major abdominal surgery: A case-control study with propensity matching.

BACKGROUND: Goal-directed fluid therapy (GDFT) has been associated with improved patient outcomes. However, implementation of GDFT protocols remains low despite growing published evidence and the recommendations of multiple regulatory bodies in Europe. We developed a closed-loop-assisted GDFT management system linked to a pulse contour monitor to assist anaesthesiologists in applying GDFT. OBJECTIVE: To assess the impact of our closed-loop system in patients undergoing major abdominal surgery in an academic hospital without a GDFT programme. DESIGN: A case-control study with propensity matching. SETTING: Operating rooms, Erasme Hospital, Brussels. PATIENTS: All patients who underwent elective open major abdominal surgery between January 2013 and December 2016. INTERVENTION: Implementation of our closed-loop-assisted GDFT in April 2015. METHODS: A total of 104 patients managed with closed-loop-assisted GDFT were paired with a historical cohort of 104 consecutive non-GDFT patients. The historical control group consisted of patients treated before the implementation of the closed-loop-system, and who did not receive GDFT. In the closed-loop group, the system delivered a baseline crystalloid infusion of 3 ml kg h and additional 100 ml fluid boluses of either a crystalloid or colloid for haemodynamic optimisation. MAIN OUTCOME MEASURES: The primary outcome was intra-operative net fluid balance. Secondary outcomes were composite major postoperative complications, composite minor postoperative complications and hospital length of stay (LOS). RESULTS: Baseline characteristics were similar in both groups. Patients in the closed-loop group had a lower net intra-operative fluid balance compared with the historical group (median interquartile range [IQR] 2.9 [1.6 to 4.4] vs. 6.2 [4.0 to 8.3] ml kg h; P < 0.001). Incidences of major and minor postoperative complications were lower (17 vs. 32%, P = 0.015 and 31 vs. 45%, P = 0.032, respectively) and hospital LOS shorter [median (IQR) 10 (6 to 15) vs. 12 (9 to 18) days, P = 0.022] in the closed-loop group. CONCLUSION: Implementation of our closed-loop-assisted GDFT strategy resulted in a reduction in intra-operative net fluid balance, which was associated with reduced postoperative complications and shorter hospital LOS. TRIAL REGISTRATION NUMBER: NCT02978430.

The place of fibrinogen concentrates in the management of perioperative bleeding: A position paper from the Francophone Working Group on Perioperative Haemostasis (GIHP).

The consumption of fibrinogen concentrates has been increasing steadily for several years in surgery, trauma and obstetrics. However, data from the literature are conflicting. The French Working Group on Perioperative Haemostasis (GIHP) proposes a position paper based on a narrative review of the literature, and addresses the following questions: What is the exact role of fibrinogen in haemostasis? Which rational support for the use of perioperative fibrinogen? Which thrombotic risk? What are the most recent professional recommendations on the use of fibrinogen concentrates? Then, evidence-based recommendations are proposed: 1) it is suggested not to administer prophylactic FC to prevent haemorrhage; 2) it is suggested not to use FC alone. Haemostatic treatment must be comprehensive, include other haemostatic treatments and must be limited in cases of severe active haemorrhage; 3) the GIHP suggests urgent measurement of fibrinogen plasma concentration in a biology laboratory or functional fibrinogen by viscoelastic methods. The choice between the two methods must be guided by the time to receive the results from a certified organisation with, in particular, authorisation to perform delocalised biologic examinations; 4) it is suggested not to administer FC when the fibrinogen concentration is superior to 1.5g/L or when there is a functional fibrinogen deficit (with the possible exception in obstetrics where the threshold could be 2.0g/L); 5) if FC are administered, an initial dose of 25-50mg/kg is proposed.

Crystalloid versus Colloid for Intraoperative Goal-directed Fluid Therapy Using a Closed-loop System: A Randomized, Double-blinded, Controlled Trial in Major Abdominal Surgery.

BACKGROUND: The type of fluid and volume regimen given intraoperatively both can impact patient outcome after major surgery. This two-arm, parallel, randomized controlled, double-blind, bi-center superiority study tested the hypothesis that when using closed-loop assisted goal-directed fluid therapy, balanced colloids are associated with fewer postoperative complications compared to balanced crystalloids in patients having major elective abdominal surgery. METHODS: One hundred and sixty patients were enrolled in the protocol. All patients had maintenance-balanced crystalloid administration of 3 ml · kg · h. A closed-loop system delivered additional 100-ml fluid boluses (patients were randomized to receive either a balanced-crystalloid or colloid solution) according to a predefined goal-directed strategy, using a stroke volume and stroke volume variation monitor. All patients were included in the analysis. The primary outcome was the Post-Operative Morbidity Survey score, a nine-domain scale, at day 2 postsurgery. Secondary outcomes included all postoperative complications. RESULTS: Patients randomized in the colloid group had a lower Post-Operative Morbidity Survey score (median [interquartile range] of 2 [1 to 3] vs. 3 [1 to 4], difference -1 [95% CI, -1 to 0]; P < 0.001) and a lower incidence of postoperative complications. Total volume of fluid administered intraoperatively and net fluid balance were significantly lower in the colloid group. CONCLUSIONS: Under our study conditions, a colloid-based goal-directed fluid therapy was associated with fewer postoperative complications than a crystalloid one. This beneficial effect may be related to a lower intraoperative fluid balance when a balanced colloid was used. However, given the study design, the mechanism for the difference cannot be determined with certainty.

Perioperative management of patients on direct oral anticoagulants.

Direct oral anticoagulants (DOACs) have been licensed worldwide for several years for various indications. Each year, 10-15% of patients on oral anticoagulants will undergo an invasive procedure and expert groups have issued several guidelines on perioperative management in such situations. The perioperative guidelines have undergone numerous updates as clinical experience of emergency management has increased and perioperative studies including measurement of residual anticoagulant levels have been published. The high inter-patient variability of DOAC plasma levels has challenged the traditional recommendation that perioperative DOAC interruption should be based only on the elimination half-life of DOACs, especially before invasive procedures carrying a high risk of bleeding. Furthermore, recent publications have highlighted the potential danger of heparin bridging use when DOACs are stopped before an invasive procedure. As antidotes are progressively becoming available to manage severe bleeding or urgent procedures in patients on DOACs, accurate laboratory tests have become the standard to guide their administration and their actions need to be well understood by clinicians. This review aims to provide a systematic approach to managing patients on DOACs, based on recent updates of various perioperative guidance, and highlighting the advantages and limits of recommendations based on pharmacokinetic properties and laboratory tests.

Tranexamic acid decreases the magnitude of platelet dysfunction in aspirin-free patients undergoing cardiac surgery with cardiopulmonary bypass: a pilot study.

This study sought to compare the effect of tranexamic acid (TXA) administration on cardiopulmonary bypass-induced platelet dysfunction in patients who received preoperative aspirin or not. We performed a prospective, randomized, double-blind pilot study, including patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). Patients without aspirin interruption were enrolled in the 'group ASPIRIN' (n = 18) and those who had never been treated with aspirin were included in the 'group NO ASPIRIN' (n = 10). Patients were then randomized to receive either TXA or the same infusion of normal saline. Multiple electrode aggregometry was used to assess platelet function at the different time points throughout the surgery: baseline, post-TXA loading dose, aortic unclamping (End CPB), and 5 min after protamine (Protamine). Compared to those included in the group NO ASPIRIN, patients included in the group ASPIRIN presented a decreased baseline platelet function measured by ASP test (P < 0.01) and collagen test (P < 0.01). In the group NO ASPIRIN, treatment group (TXA vs. placebo) significantly influenced the results for ADP test (P < 0.01), thrombin receptor-activating peptide test (P = 0.01), and ASP test (P = 0.01). We observed that TXA improved platelet function, as measured using multiple electrode aggregometry on ADP test, thrombin receptor-activating peptide test, and ASP test, at the end of CPB (P < 0.05). TXA might decrease the magnitude of platelet dysfunction in aspirin-free patients undergoing cardiac surgery. Further studies are needed to confirm these results and assess a potential relationship with clinical endpoints.

Evaluation of total body weight and body mass index cut-offs for increased cefazolin dose for surgical prophylaxis.

French and American guidelines recommend increased dosage regimens of cefazolin (CFZ) for surgical prophylaxis in patients with a body mass index (BMI) ≥ 35 kg/m2 or with a total body weight (TBW) ≥ 120 kg. The objective of this study was to evaluate the accuracy of these cut-offs in identifying patients who require CFZ dose adjustment. A pharmacokinetic study was conducted in patients of varying TBW and BMI who received 2 g of CFZ intravenously for prophylaxis prior to digestive surgery. Adequacy of therapy, defined as a serum concentration of unbound CFZ (fCFZ) ≥ 4 mg/L, was evaluated 180 min (T180) and 240 min (T240) after the start of CFZ infusion. Possible factors associated with insufficient fCFZ levels were also assessed. A P-value of <0.05 was considered statistically significant. A total of 63 patients were included in the study, categorised according to BMI (<35 kg/m2, 20 patients; and ≥35 kg/m2, 43 patients) and TBW (<120 kg, 41 patients; and ≥120 kg, 22 patients). All patients had adequate drug levels at T180 but only 40/63 patients (63%) had adequate levels at T240. At T240, therapy was adequate in 15/20 patients (75%) and 25/43 patients (58%) with BMI <35 kg/m2 and ≥35 kg/m2, respectively (P = 0.20), and in 28/41 patients (68%) and 12/22 patients (55%) with TBW <120 kg and ≥120 kg, respectively (P = 0.28). No factor associated with insufficient fCFZ was identified. In conclusion, current BMI and TBW cut-offs are poor indicators of which patients could benefit from increased CFZ dosage regimens.

Effect of two doses of tranexamic acid on fibrinolysis evaluated by thromboelastography during cardiac surgery: a randomised, controlled study.

BACKGROUND: Tranexamic acid is used to decrease bleeding and transfusions during cardiac surgery. However, dosing based on pharmacokinetic data to optimally inhibit fibrinolysis is unknown. With increasing concerns regarding seizures associated with higher doses, lower dosing schemes may be important. OBJECTIVE: To determine the effect of two dosing schemes compared with placebo on fibrinolysis and clinical outcomes. DESIGN: A double-blind, randomised, controlled, pilot trial. SETTING: Single tertiary centre. PATIENTS: Cardiac surgery patients requiring cardiopulmonary bypass. INTERVENTION: Patients were randomised to receive a 30 mg  kg(-1) bolus and continuous infusion of 16  mg  kg (-1) h(-1) (Group HIGH), a 5 mg  kg(-1) bolus followed by 5 mg  kg(-1)  h(-1) (Group LOW) or Sodium chloride (Placebo). MAIN OUTCOME MEASURE: Fibrinolysis was evaluated by thromboelastography and D-dimers. Secondary endpoints were blood loss, transfusion requirement and side effects. RESULTS: Thirty-three patients were included. Significant fibrinolysis was defined by LY30 more than 7.5% based on thromboelastography and was not observed after cardiopulmonary bypass in any groups. After protamine administration, LY30 differences between groups were 0.7 [95% confidence interval (95% CI) -0.04 to 1.4] between Groups HIGH and Placebo, -0.08 (95% CI -0.82 to 0.66) between Groups HIGH and LOW, and 0.78 (95% CI 0.02 to 1.5) between Groups LOW and Placebo. A significant increase in D-dimers was observed in the Group Placebo compared with the two treatment groups. There were no differences in bleeding or transfusion requirement. CONCLUSION: In this dose-finding study, there were no differences in fibrinolysis or clinical outcomes among the two tranexamic acid schemes and placebo. Any difference in fibrinolytic inhibition requires a larger adequately powered study. TRIAL REGISTRATION: EudraCT number: 2010-024104-99.