Grégoire Weil

Measurement of Cardiac Index by Transpulmonary Thermodilution Using an Implanted Central Venous Access Port: A Prospective Study in Patients Scheduled for Oncologic High-Risk Surgery

Background Transpulmonary thermodilution allows the measurement of cardiac index for high risk surgical patients. Oncologic patients often have a central venous access (port-a-catheter) for chronic treatment. The validity of the measurement by a port-a-catheter of the absolute cardiac index and the detection of changes in cardiac index induced by fluid challenge are unknown. Methods We conducted a monocentric prospective study. 27 patients were enrolled. 250 ml colloid volume expansions for fluid challenge were performed during ovarian cytoreductive surgery. The volume expansion-induced changes in cardiac index measured by transpulmonary thermodilution by a central venous access (CIcvc) and by a port-a-catheter (CIport) were recorded. Results 23 patients were analyzed with 123 pairs of measurements. Using a Bland and Altman for repeated measurements, the bias (lower and upper limits of agreement) between CIport and CIcvc was 0.14 (−0.59 to 0.88) L/min/m2. The percentage error was 22%. The concordance between the changes in CIport and CIcvc observed during volume expansion was 92% with an r = 0.7 (with exclusion zone). No complications (included sepsis) were observed during the follow up period. Conclusions The transpulmonary thermodilution by a port-a-catheter is reliable for absolute values estimation of cardiac index and for measurement of the variation after fluid challenge. Trial Registration clinicaltrials.gov NCT02063009

Learning curves for three specific procedures by anesthesiology residents using the learning curve cumulative sum (LC-CUSUM) test

Background The learning curve cumulative sum (LC-CUSUM) test is an innovative tool that allows quantitative monitoring of individual medical performance during the learning process by determining when a predefined acceptable level of performance is reached. This study used the LC-CUSUM test to monitor the learning process and failure rate of anesthesia residents training for specific subspecialty anesthesia procedures. Methods The study included 490 tracheal punctures (TP) for jet ventilation, 340 thoracic epidural analgesia (TEA) procedures, and 246 fiberoptic nasal intubations (FONI) performed by 18 residents during their single 6-month rotation. Results Overall, 27 (14–52), 19 (5–41), and 14 (6–33) TP, TEA, and FONI procedures were performed, respectively, by each resident. In total, 2 of 18 residents achieved an acceptable failure rate for TEA according to the literature and 4 of 18 achieved an acceptable failure rate for FONI, while none of the residents attained an acceptable rate for TP. Conclusions A single 6-month rotation in a reference teaching center may not be sufficient to train residents to perform specific or sub-specialty procedures as required. A regional learning network may be useful. More patient-based data are necessary to conduct a risk adjustment analysis for such specific procedures.

Remote peripheral tissue oxygenation does not predict postoperative free flap complications in complex head and neck cancer surgery: A prospective cohort study

BACKGROUND Patients undergoing free flap reconstruction after head and neck cancer may develop free flap complications. In the perioperative period, haemoglobin content and oxygen tissue saturation (StO2) measured directly on the free flap reflect peripheral tissue oxygenation. However, in this type of surgery, StO2 cannot always be applied directly or proximate to the free flap. The aim of this study was to assess the possible value of StO2 measured at the thenar eminence and other 24hour perioperative factors on free flap complications. METHODS Inclusion criteria corresponded to patients with head and neck cancer with free flap surgery in whom direct StO2 could not be monitored on the flap nor in its peripheral area. Patient characteristics and intraoperative data, such as haemoglobin and fluid management, were prospectively collected. StO2 was measured remotely on the thenar eminence. Data were collected for 24hours and free flap complications were recorded for up to 15days after surgery. Patients were thereafter classified into two groups: with or without free flap complications and the data were compared in consequence. RESULTS Forty consecutive patients were prospectively included. Ten patients had postoperative free flap complications and were compared to the 30 other patients without complications. The haemoglobin level at the reperfusion of the flap: (AUC 0.80 [0.65-0.91], threshold 9.9g/dL, P<0.001) and body mass index [BMI] (AUC 0.80 [0.64-0.72], threshold 24.5kg/m2, P<0.01) were significantly related to complications. CONCLUSION In head and neck complex oncologic reconstructive surgery, haemoglobin and BMI were the most sensitive tools for predicting postoperative free flap complications, while thenar eminence StO2 was not.

Comparaison de quatre masques laryngés à usage unique pour la chirurgie carcinologique du sein : une approche médico-économique☆☆☆

OBJECTIVE The main goal of this study was to achieve a medico-economic comparison between four disposable laryngeal masks (LM) (LMA-Unique™, Ambu AuraOnce™, I-Gel™ and LMA-Suprême™). STUDY DESIGN A prospective, randomized, monocentre study. MATERIAL AND METHODS In a center, using routinely LMA-Unique masks, scheduled breast surgery patients were allocated into four groups according to the LM model. After the induction, the modalities of use were collected, as well as the intraoperative events that required additional anesthetic equipment. The real cost of each model was calculated (cost of the mask+extra cost related to complications). Using the LMA-Unique as a reference, we performed a cost-efficacy analysis. We realized a cost-efficiency analysis putting in parallel the impact on the cost and the incidence of the events. RESULTS A total of 178 patients were included. According to the cost-efficacy analysis, the dominant model was the Ambu AuraOnce™ (Δreal cost: -34.2%, Δevents: -30.6%). The LMA-Unique™ was dominated because of a high morbidity rate. The I-Gel™ and LMA-Suprême™ models were more efficient but more expensive (Δreal cost: +16% and +22.5% respectively). To compensate for additional costs, it would be necessary to apply a price reduction of at least 50%. CONCLUSIONS Despite their better efficiency and safety, the latest generation laryngeal masks are still expensive in spite of a low rate of complication. These results do not take into account very rare and severe complications not met in this study in the limited size; then the economic and medical impact can influence the choice beyond the simple analysis cost-efficiency.

Comparison of Proaqt/Pulsioflex® and oesophageal Doppler for intraoperative haemodynamic monitoring during intermediate-risk abdominal surgery

OBJECTIVE To compare cardiac index (CI) between Proaqt/PulsioFlex® and oesophageal Doppler (OD) and the ability of the PulsioFlex® to track CI changes induced by fluid challenge and secondly to assess the impact of the time interval between two auto-calibrations of PulsioFlex® on the accuracy of the measured CI. METHODS In a single hospital, 49 intermediate-risk oncologic abdominal surgery patients were included in an observational study. We measured the cardiac Index (CI) provided by OD and by the Proaqt/PulsioFlex® before and after internal calibration, which were performed randomly at specific intervals after the initial one (30, 60, 90 and 120min). The ability to track fluid responsiveness was evaluated by measuring stroke volume variation, pulse pressure variation (PPV) and CI before and after a 250ml fluid challenge and assessed by a receiver operating characteristic curve analysis. RESULTS The percentages of error before calibration were 51, 58, 82, 81% for 30, 60, 90 and 120min, they were 39, 57, 65, and 54% after calibration. Trending ability is assumed by a 93% concordance rate after applying a 15% exclusion zone. The trend interchangeability rate was 13.75%. The area under the curve for fluid responsiveness measured by PPV and SVV PulsioFlex were respectively 0.67 [0.57-0.77], P<0.01 and 0.75 [0.47-0.66], which was not clinically relevant. CONCLUSIONS The Proaqt/Pulsioflex® system is not equivalent to OD for haemodynamic monitoring during non-vascular abdominal surgery in intermediate-risk patients. More studies are required to define the effect of the auto-calibration on the system.

Système de boucle fermée pour l’optimisation hémodynamique peropératoire : l’anesthésie a encore à apprendre de l’aéronautique

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