End-Expiratory Occlusion Test to Predict Fluid Responsiveness Is Not Suitable for Laparotomic Surgery.

BACKGROUND: The end-expiratory occlusion test predicts fluid responsiveness in ventilated intensive care patients; however, its utility in the operating room is questioned. We assessed end-expiratory occlusion test in laparotomic surgery for predicting volume expansion. METHODS: Forty-six patients were included in this study: stage 1 (n = 26) with an end-expiratory occlusion test of 15 seconds, followed by volume expansion, which consisted of 250 mL of colloid over 5 minutes and stage 2 (n = 20) with an end-expiratory occlusion test of 25 seconds followed by volume expansion. The last 10 patients had transdiaphragmatic pressures probed. Patients with an increase in cardiac index >15% after volume expansion were responders. Pulse pressure variation, stroke volume (SV) index, and cardiac index were analyzed. Receiver operating characteristic curves were established for changes in SV and pulse pressure induced by end-expiratory occlusion test and pulse pressure variation using the responders status for volume expansion as outcome. RESULTS: A total of 44 (38%) volume expansions were deemed responders. After end-expiratory occlusion test of 15 seconds, no hemodynamic variables were significantly increased. After end-expiratory occlusion test of 25 seconds, SV index increased in responders (37.1 ± 8.8 mL/m after end-expiratory occlusion test of 25 seconds versus 35.7 ± 8.6 before; P < .0001). End-expiratory occlusion test could not discriminate responders from nonresponders. Only pulse pressure variation had significantly different area under the curve from that expected by chance (0.7 [0.57-0.81]; P = .002 for end-expiratory occlusion test of 15 seconds; and 0.78 [0.64-0.89]; P = .0001 for end-expiratory occlusion test of 25 seconds). After laparotomy, gastric pressure decreased significantly (4 [2.75-5] vs 2 [2-4] cm H2O; P = .0417); no difference was noticed in the transdiaphragmatic gradient. CONCLUSIONS: End-expiratory occlusion test was not reliable to discriminate responders from nonresponders after volume expansion during laparotomic surgery.

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.

A Hemodynamic Monitor as a Simulation Tool, a Novel Use of the PiCCO2: Technical Description of the Method and Its Application.

INTRODUCTION: The PiCCO2 is a commonly used monitor, which education remains theoretical and demonstration based. Simulation allows active learning, which may help achieve a better understanding and handling of this device, hence a safer and more effective use. Because of the lack of availability of dedicated simulators and the uselessness of the demonstration mode of monitors for simulation purpose, simulation remains seldom used. We will describe a novel use of the PiCCO2 for simulation training and its experiment in high-fidelity simulation (HFS). METHODS: A standard PiCCO2 was modified with software allowing its transformation into a simulator. The values displayed on the screen were managed in real time by an operator using a standard laptop linked to the monitor and using a standard disposable catheter set to execute simulated transpulmonary thermodilution. Nineteen volunteers were requested to assess the realism of the device during scenarios in which the PiCCO2S (simulator) was used in an HFS environment, with a mannequin reproducing a septic shock condition. RESULTS: Two experimental sessions were made. PiCCO2S was used in the contextualized setting of HFS, which allowed a good interactivity between the device and its users. Participants had a positive perception of the realism as well as the method's adequacy to achieve a better understanding of the PiCCO2. CONCLUSIONS: The PiCCO2S could be obtained from a serial device. Its integration in HFS provided a realistic handling of the device. A built-in simulation mode into serial medical devices may give users an easy access to training.

How to rationalize preoperative tests? A method to implement local guidelines successfully.

BACKGROUND: Preoperative screening includes clinical examination and tests. Systematic prescription leads to excessive tests. We conducted an observational retrospective study to assess the success of implementing a protocol-guided prescription procedure for preoperative tests (PTs). We compared the number of PTs prescribed for scheduled surgery before and after the implementation of local guidelines with a specific method. METHODS: Local guidelines for prescribing PTs based on the French Society of Anaesthesia's recommendations were developed, validated by the anaesthesia team and actively implemented. The implementation procedure was complex and based on the application of sociologic concepts to facilitate PT prescriptions in accordance with the protocol. All PTs (except for children and emergency surgeries) prescribed over a one-week observation period were analysed before and after protocol implementation, respectively in 2011 and 2013. RESULTS: Two hundred and ninety-two patient files were analysed: 157 in 2011 and 135 in 2013. Ninety-one percent of the prescriptions were in accordance with the recommendations in 2013. Excessive prescribing decreased significantly after the implementation of recommendations (7.1% versus 20.7%, P<0.0001), enabling us to reduce excess costs. CONCLUSION: We observed excellent adherence to the prescription protocol for PTs. The method used to implement the protocol was successful. A future evaluation should be undertaken to confirm these results over the long-term.

The use of a clinical database in an anesthesia unit: focus on its limits.

Anesthesia information management system (AIMS) can be used a part of quality assurance program to improve patient care, however erroneous or missing data entries may lead to misinterpretation. This study assesses the accuracy of information extracted for six consecutive years from a database linked to an automatic anesthesia record-keeping system. An observational study was conducted on a database linked AIMS system. The database was filled in real time during surgical/anesthesia procedure and in the post-anesthesia care unit. The following items: name of the anesthetist, duration of anesthesia, duration of monitoring, ventilatory status upon arrival in postoperative care unit, pain scores, nausea and vomiting scores, pain medication (morphine) and anti nausea and vomiting drug consumption (ondansetron) were extracted and analysed in order to determine exhaustivity (percentage of missing data) and accuracy of the database. The analysis covered 55,946 anaesthetic procedures. The rate of missing data was initially high upon installation but decreased over time. It was limited to 5% after 3 years for items such as start of anesthesia or name of the anesthetist. However exhaustivity/completeness of some other variable, such as nausea and vomiting started as low as 50% to reach 20% at 2008. After cross analysing pain and post-operative nausea and vomiting scores with related medication consumption, (morphine and ondansetron) we conclude that missing data was due to omission of a zero score rather than human error. The follow-up of quality assurance program may use data from AIMS provided that missing or erroneous values be mentioned and their impact on calculations accurately analysed.

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.