Individualised or liberal red blood cell transfusion after cardiac surgery: a randomised controlled trial.

BACKGROUND: Current practice guidelines for red blood cell (RBC) transfusion in ICUs are based on haemoglobin threshold, without consideration of oxygen delivery or consumption. We aimed to evaluate an individual physiological threshold-guided by central venous oxygen saturation ScvO2. METHODS: In a randomised study in two French academic hospitals, 164 patients who were admitted to ICU after cardiac surgery with postoperative haemoglobin <9 g dl-1 were randomised to receive a transfusion with one unit of RBCs (haemoglobin group) or transfusion only if the ScvO2 was <70% (individualised group). The primary outcome was the number of subjects receiving at least one unit of RBCs. The secondary composite outcome was acute kidney injury, stroke, myocardial infarction, acute heart failure, mesenteric ischaemia, or in-hospital mortality. One- and 6-month mortality were evaluated during follow-up. RESULTS: The primary outcome was observed for 80 of 80 subjects (100%) in the haemoglobin group and in 61 of 77 patients (79%) in the individualised group (absolute risk -21% [-32.0; -14.0]; P<0.001). There was no significant difference in the secondary outcome between the two groups. Follow-up showed a non-significant difference in mortality at 1 and 6 months. CONCLUSIONS: An individualised strategy based on an central venous oxygen saturation threshold of 70% allows for a more restrictive red blood cell transfusion strategy with no incidence on postoperative morbidity or 6-month mortality. CLINICAL TRIAL REGISTRATION: NCT02963883.

Perioperative non-invasive haemodynamic optimisation using photoplethysmography: A randomised controlled trial and meta-analysis.

BACKGROUND: The present study aimed at evaluating the effect of a haemodynamic algorithm using SV maximisation by non-invasive photoplethysmography (interventional group) on the incidence of postoperative complications compared with a control group using intermittent mean arterial pressure. METHODS: The non-blinded parallel-group trial randomised low-risk patients undergoing colorectal surgery into either interventional group or control group. The primary outcome was the incidence of patients with at least one complication during the 30 days following surgery. The secondary outcomes were the total number of complications, the length of hospital stay and postoperative mortality. A meta-analysis of randomised trials comparing perioperative haemodynamic optimisation (interventional group) using photoplethysmography with control group was performed to assess the external validity. RESULTS: Among 160 randomised patients, 159 were analysed (80 and 79 in interventional and control groups, respectively). Demographic characteristics were similar in both groups. Postoperative complications occurred in 40 (50%) and 34 (43%) patients in the interventional and control groups, respectively (P=0.471). There were no significant differences between the two groups regarding the total number of complications (P=0.078), the hospital length of stay (P=0.960), or postoperative mortality (P=1.000). In the meta-analysis including 1089 patients in 7 randomised controlled studies, 203 (38%) and 221 (40%) patients suffered from at least one complication following surgery [risk ratio 0.89 (95% CI 0.68-1.17), P=0.407] in interventional and control groups, respectively. CONCLUSIONS: Based on the findings of the present study and meta-analysis, a haemodynamic perioperative algorithm using SV maximisation by non-invasive photoplethysmography cannot reduce postoperative morbidity.

Interchangeability of cardiac output measurements between non-invasive photoplethysmography and bolus thermodilution: A systematic review and individual patient data meta-analysis.

BACKGROUND: Continuous non-invasive cardiac output devices using digital photoplethysmography (PPG) are widely available for bedside use, but their interchangeability with reference methods has not yet been evaluated in a systematic review and patient data meta-analysis. METHODS: A systematic review and meta-analysis of studies comparing non-invasive cardiac output monitoring using PPG with the invasive bolus thermodilution method was performed. With ethical approval, all published studies from the PUBMED, Embase, Scopus, Web of Science, and Google Scholar databases from January 1, 2010 to January 1, 2018 were included. From these analysed studies, individual patient data were interpreted using the interchangeability methods for both absolute values and changes in cardiac output measurements. RESULTS: Ten studies comparing PPG and bolus thermodilution in the operating room and intensive care settings were included. The interchangeability rate (95% CI) was 37% (24-48) (n=1350 pairs of measurements). The interchangeability rate was poorer with the CNAP device (CNSystems, Graz, Austria) [18% (17-20)] than with the Clearsight (Edwards Lifesciences, Irvine, CA) device [33% (31-34), P<0.0001], for patients receiving norepinephrine [19% (17-20) vs. 33% (32-34), P<0.0001], and for patients with low mean arterial pressure (<65mmHg) [26% (23-29) vs. 30% (29-31), P<0.0001]. Among the 1009 comparisons of the changes in cardiac output between both methods, 561 (56%) were interpretable with a trend interchangeability rate at 24% (12-36). CONCLUSIONS: Cardiac output measurements using PPG were not interchangeable with bolus thermodilution in regard to both absolute values and changes in cardiac output measurements, and should be used with caution in clinical practice. TRIAL REGISTRATION: PROSPERO ID CRD42018089513.

Perioperative hemodynamic optimization using the photoplethysmography in colorectal surgery (the PANEX3 trial): study protocol for a randomized controlled trial.

BACKGROUND: Photoplethysmography with a digital sensor (ClearSight, Edwards Lifesciences, Irvine, CA, USA) connected to a dedicated monitor (EV 1000, Edwards Lifesciences) was recently proposed for use in performing hemodynamic optimization during surgery. The objective of this study is to evaluate the effect of photoplethysmography on the incidence of postoperative complications compared with the conventional hemodynamic algorithm, which uses mean arterial pressure. METHODS/DESIGN: The hemodynamic optimization using photoplethysmography (PANEX3) trial is a monocentric, randomized, single-blind, controlled, two parallel arm, superiority trial, randomizing 160 patients with an intermediate risk of postoperative complications after colorectal surgery. Informed consent will be obtained from all participants. The hemodynamic optimization is conducted using a specified hemodynamic algorithm either with photoplethysmography (the photoplethysmography group) or with conventional mean arterial pressure (the control group). The anesthesiologist performed a 1:1 randomization the day before surgery using a scratch card, which is available 24/7. The randomization sequence is generated using permutated blocks. Both the patients and surgeons are blinded to the allocation group. The primary outcome is the incidence of at least one postoperative complication during the 30 days following surgery. Two independent experts, who were blinded to the group allocations, validate the complication for each patient using an a priori classification. The secondary outcomes are to study the total number of postoperative complications, the real length of hospital stays, and the postoperative mortality between each group. DISCUSSION: The PANEX3 trial is the first randomized controlled study conducted to investigate whether perioperative hemodynamic optimization using photoplethysmography during colorectal surgery could decrease the incidence of patients having at least one postoperative complication. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02343601.