Effects of an open lung extubation strategy compared with a conventional extubation strategy on postoperative pulmonary complications after general anesthesia: a single-centre pilot randomized controlled trial.

PURPOSE: Postoperative pulmonary complications (PPCs) are a common cause of morbidity. Postoperative atelectasis is thought to be a significant risk factor in their development. Recent imaging studies suggest that patients' extubation may result in similar postoperative atelectasis regardless of the intraoperative mechanical ventilation strategy used. In this pilot trial, we hypothesized that a study investigating the effects of an open lung extubation strategy compared with a conventional one on PPCs would be feasible. METHODS: We conducted a pilot, single-centre, double-blinded randomized controlled trial. Adult patients at moderate to high risk of PPCs and scheduled for elective surgery were eligible. Patients were randomized to an open lung extubation strategy (semirecumbent position, fraction of inspired oxygen [FIO2] 50%, pressure support ventilation, unchanged positive end-expiratory pressure) or to a conventional extubation strategy (dorsal decubitus position, FIO2 100%, manual bag ventilation). The primary feasibility outcome was global protocol adherence while the primary exploratory efficacy outcome was PPCs. RESULTS: We randomized 35 patients to the conventional extubation group and 34 to the open lung extubation group. We observed a global protocol adherence of 96% (95% confidence interval, 88 to 99), which was not different between groups. Eight PPCs occurred (two in the conventional extubation group vs six in the open lung extubation group). Less postoperative supplemental oxygen and better lung aeration were observed in the open lung extubation group. CONCLUSIONS: In this single-centre pilot trial, we observed excellent feasibility. A multicentre pilot trial comparing the effect of an open lung extubation strategy with that of a conventional extubation strategy on the occurrence of PPCs is feasible. STUDY REGISTRATION DATE: ClinicalTrials.gov (NCT04993001); registered 6 August 2021.

RéSUMé: OBJECTIF: Les complications pulmonaires postopératoires (CPP) sont une cause fréquente de morbidité. L'atélectasie postopératoire est considérée comme un facteur de risque important de CPP. Des études d'imagerie récentes suggèrent que l'extubation des patient·es peut entraîner une atélectasie postopératoire semblable, quelle que soit la stratégie de ventilation mécanique peropératoire utilisée. Dans cet essai pilote, nous avons émis l'hypothèse qu'une étude examinant les effets sur les CPP d'une stratégie d'extubation à poumon ouvert par rapport à une stratégie d'extubation conventionnelle serait réalisable. MéTHODE: Nous avons mené une étude randomisée contrôlée pilote, monocentrique et à double insu. Les patient·es adultes présentant un risque modéré à élevé de CPP et devant bénéficier d'une chirurgie non urgente étaient éligibles. Les patient·es ont été randomisé·es à une prise en charge par une stratégie d'extubation à poumon ouvert (position semi-couchée, fraction d'oxygène inspiré [FIO2] 50 %, ventilation par aide inspiratoire, pression positive télé-expiratoire inchangée) ou à une stratégie d'extubation conventionnelle (décubitus dorsal, FIO2 100 %, ventilation manuelle par masque). Le principal critère de faisabilité était l'adhésion au protocole global, tandis que les CPP constituaient le principal critère d'efficacité exploratoire. RéSULTATS: Nous avons randomisé 35 patient·es dans le groupe d'extubation conventionnelle et 34 dans le groupe d'extubation à poumon ouvert. Nous avons observé une adhésion globale au protocole de 96 % (intervalle de confiance à 95 %, 88 à 99), qui n'était pas différente entre les groupes. Huit CPP sont survenues (deux dans le groupe d'extubation conventionnelle vs six dans le groupe d'extubation à poumon ouvert). Nous avons observé des besoins moins importants en oxygène supplémentaire postopératoire et une meilleure aération pulmonaire dans le groupe extubé à poumon ouvert. CONCLUSION: Dans cet essai pilote monocentrique, nous avons observé une excellente faisabilité. Une étude pilote multicentrique comparant l'effet d'une stratégie d'extubation à poumon ouvert à celui d'une stratégie d'extubation conventionnelle sur la survenue de CPP est réalisable. DATE D'ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04993001); enregistrée le 6 août 2021.

Elements not Graded in the Cardiac Enhanced Recovery After Surgery Guidelines Might Improve Postoperative Outcome: A Comprehensive Narrative Review.

Enhanced Recovery Programs (ERPs) are protocols involving the whole patient surgical journey. These protocols are based on multimodal, multidisciplinary, evidence-based, and patient-centered approaches aimed at improving patient recovery after a surgical intervention. Such programs have shown striking positive results in different surgical specialties. However, only a few research groups have incorporated preoperative, intraoperative, and postoperative evidence-based interventions in bundles used to standardize care and build cardiac surgery ERPs. The Enhanced Recovery After Surgery Society recently published evidence-based recommendations for perioperative care in cardiac surgery. Their recommendations included 22 perioperative interventions that may be part of any cardiac ERP. However, various components integrated in already-published cardiac ERPs were neither graded nor reported in these recommendations. The goals of the current review are to present published cardiac ERPs and their effects on patient outcomes and reported components incorporated into these ERPs and to discuss the objectives and scope of cardiac ERPs.

Feasibility and postoperative opioid sparing effect of an opioid-free anaesthesia in adult cardiac surgery: a retrospective study.

BACKGROUND: No previous study investigated the dexmedetomidine-based opioid-free anesthesia (OFA) protocol in cardiac surgery. The main objective of this study was to evaluate the feasibility and the postoperative opioid-sparing effect of dexmedetomidine-based OFA in adult cardiac surgery patients. METHODS: We conducted a single-centre and retrospective study including 80 patients above 18 years old who underwent on-pump cardiac surgery between November 2018 and February 2020. Patients were divided into two groups: OFA (lidocaine, ketamine, dexmedetomidine, MgSO4) or opioid-based anaesthesia (remifentanil and anti-hyperalgesic medications such as ketamine and/or MgSO4 and/or lidocaine at the discretion of the anesthesiologist). The primary endpoint was the total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours. Secondary outcomes included perioperative hemodynamics, post-operative maximal pain at rest and during coughing and adverse outcomes. Data are expressed as median [interquartile range]. RESULTS: Patients in the OFA-group had a higher EuroSCORE II, with more diabetes, more dyslipidemia and more non-elective surgery but fewer smoking history. In the OFA group, the median loading dose of dexmedetomidine was 0.6 [0.4-0.6] µg.kg- 1 while the median maintenance dose was 0.11 µg.kg- 1.h- 1 [0.05-0.20]. In 10 (25%) patients, dexmedetomidine was discontinued for a drop of mean arterial pressure below 55 mmHg. The median total amount of opioid consumed in its equivalent of intravenous morphine during the first 48 postoperative hours was lower in the OFA group (15.0 mg [8.5-23.5] versus 30.0 mg [17.3-44.3], p < 0.001). While no differences were seen with rest pain (2.0 [0.0-3.0] versus 0.5 [0.0-5.0], p = 0.60), the maximal pain score during coughing was lower in OFA group (3.5 [2.0-5.0] versus 5.5 [3.0-7.0], p = 0.04). In OFA group the incidence of atrial fibrillation (18% versus 40%, p = 0.03) and non-invasive ventilation use (25% versus 48%, p = 0.04) were lower. The incidence of bradycardia and the intraoperative use of norepinephrine were similar between both groups. CONCLUSION: Dexmedetomidine-based OFA in cardiac surgery patients is feasible and could be associated with a lower postoperative morphine consumption and better postoperative outcomes. Further randomized studies are required to confirm these promising results and determine the optimal associations, dosages, and infusion protocols during cardiac surgery.

Autonomous Systems in Anesthesia: Where Do We Stand in 2020? A Narrative Review.

As most of us are aware, almost every facet of our society is becoming, for better or worse, progressively more technology-dependent. Technological advancement has made autonomous systems, also known as robots, an integral part of our life in several fields, including medicine. The application of robots in anesthesia could be classified into 3 types of robots. The first ones are pharmacological robots. These robots are based on closed-loop systems that allow better-individualized anesthetic drug titration for optimal homeostasis during general anesthesia and sedation. Recent evidence also demonstrates that autonomous systems could control hemodynamic parameters proficiently outperforming manual control in the operating room. The second type of robot is mechanical. They enable automated motorized reproduction of tasks requiring high manual dexterity level. Such robots have been advocated to be more accurate than humans and, thus, could be safer for the patient. The third type is a cognitive robot also known as decision support system. This type of robot is able to recognize crucial clinical situation that requires human intervention. When these events occur, the system notifies the attending clinician, describes relevant related clinical observations, proposes pertinent therapeutic options and, when allowed by the attending clinician, may even administer treatment. It seems that cognitive robots could increase patients' safety. Robots in anesthesia offer not only the possibility to free the attending clinicians from repetitive tasks but can also reduce mental workload allowing them to focus on tasks that require human intelligence such as analytical and clinical approach, lifesaving decision-making capacity, and interpersonal interaction. Nevertheless, further studies have yet to be done to test the combination of these 3 types of robots to maintain simultaneously the homeostasis of multiple biological variables and to test the safety of such combination on a large-scale population.

U-shaped relationship between pre-operative plasma fibrinogen levels and severe peri-operative bleeding in cardiac surgery.

BACKGROUND: An inverse linear relationship has been reported between pre-operative fibrinogen levels and postoperative blood loss in cardiac surgery. However, recently high pre-operative fibrinogen levels have also been reported to be associated with increased blood transfusion and re-operation. OBJECTIVE: We tested the hypothesis that the relationship between pre-operative fibrinogen levels and severe peri-operative bleeding is not linear. DESIGN: A large-scale (n = 3883) single-centre retrospective study. SETTING: A tertiary care teaching hospital. PATIENTS: We analysed data from our institutional database which includes all patients above 18 years who underwent on-pump cardiac surgery through a sternotomy between September 2010 and May 2014. MAIN OUTCOME MEASURES: Peri-operative severe bleeding adapted from the Universal Definition of Peri-operative Bleeding, class 3 or 4. The relationship between pre-operative fibrinogen levels and peri-operative severe bleeding was analysed by binary logistic regression. A cubic B-spline transformation was used to estimate the relationship between pre-operative fibrinogen level associated with excessive peri-operative bleeding. RESULTS: Severe peri-operative bleeding was observed in 957 (24.6%) patients. An L-shaped relationship was observed between pre-operative fibrinogen levels and 24-h postoperative blood loss. The relationship between pre-operative fibrinogen levels and severe peri-operative bleeding (i.e. Universal Definition of Peri-operative Bleeding class 3 or 4) was U-shaped: the risk of severe peri-operative bleeding bottomed at 3.3 g l when the upward sloping curve started at 5.8 g l with a steeper increase above 8.2 g l. CONCLUSION: We reported a U-shaped relationship between severe peri-operative bleeding and pre-operative fibrinogen levels. While a low-level of fibrinogen appears to be associated with a high risk of bleeding, a high level does not necessarily protect the patient against such a risk and could even be a risk factor for peri-operative bleeding.

Automated systems for perioperative goal-directed hemodynamic therapy.

Perioperative goal-directed hemodynamic therapy (GDHT) has evolved from invasive "supra-physiological" maximization of oxygen delivery to minimally or even noninvasively guided automated stroke volume optimization. Over the past four decades, investigators have simultaneously developed novel monitors, updated strategies, and automated technologies to improve GDHT. Decision support technology, which proposes an intervention based on the patient's real time physiologic status, was an important step towards automation. Closed-loop systems have now been created to both increase GDHT compliance and decrease physician workload. These automated systems offer an elegant approach to optimize cardiac output and end-organ perfusion during the perioperative period. Most notably, automated preload optimization guided by dynamic indicators of fluid responsiveness has shown its feasibility, safety, and impact. Making the leap into fully automated GDHT has been accomplished on a small scale, but there are considerable challenges that must be surpassed before integrating all hemodynamic components into an automated system during general anesthesia. In this review, we will discuss the evolution and potential future of automated GDHT during the perioperative period.

Reduced Length of Hospital Stay for Cardiac Surgery-Implementing an Optimized Perioperative Pathway: Prospective Evaluation of an Enhanced Recovery After Surgery Program Designed for Mini-Invasive Aortic Valve Replacement.

OBJECTIVES: Presently, there is enthusiasm for the Enhanced Recovery After Surgery (ERAS) program. The literature clearly indicates this type of program could shorten hospital length of stay and improve patient outcome. However, most of the studies conducted have encompassed mainly colorectal and orthopedic surgeries. Thus, in an effort to provide more evidence to the literature, the authors prospectively investigated the feasibility and clinical effectiveness of a dedicated ERAS program for mini-invasive aortic valve replacements (MIAVRs). DESIGN: Observational before-and-after trial. SETTING: University hospital. PARTICIPANTS: Consecutive patients scheduled for an MIAVR via a mini-sternotomy during 2 time periods-before (MIAVR group) and after implementation of an ERAS program (MIAVR-ERAS group). INTERVENTIONS: Patients in the dedicated MIAVR-ERAS group followed a dedicated pathway specifically designed for this procedure, which encompasses several evidence-based medicine elements for cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Data on patient demographics, patient characteristics, compliance to the ERAS protocol, postoperative morphine consumption, postoperative pain scores, postoperative complications, hospital length of stay, and hospital readmission rate were collected and compared. Twenty-three patients were enrolled in each group. Patients enrolled in the new protocol had significantly lower postoperative pain scores (p = 0.03). The median hospital length of stay was 10 (9-13.5) and 7 (6.5-8) days in the traditional MIAVR group and in the MIAVR-ERAS group, respectively (p < 0.001). CONCLUSIONS: An ERAS pathway planned for MIAVR seems feasible and was associated with a shorter length of hospital stay with trends toward both less opioid consumption and less postoperative complications.

Intraoperative changes in blood lactate levels are associated with worse short-term outcomes after cardiac surgery with cardiopulmonary bypass.

BACKGROUND: A high perioperative blood lactate level has been reported to be associated with poor outcomes after cardiac surgery. More than isolated peaks of lactate values, it should be more interesting to take into account changes in intraoperative blood lactate level (∆Lact). This large-scale retrospective study evaluated the relationship between ∆Lact and overall intensive care unit morbidity and 30-day all-cause mortality. METHODS: Perioperative data from consecutive patients undergoing on-pump cardiac surgery between September 2010 and June 2016 were retrospectively analysed through our institutional database including clinical, transfusion and laboratory test results implemented prospectively by physicians. Blood lactate levels were initially measured after induction of anaesthesia (baseline) and periodically during the surgery. The ∆Lact was defined as the difference between the highest intraoperative blood lactate and the baseline lactate level and offered the opportunity to stratify patients into four subgroups: ⩽0, 0.1-0.9, 1-1.9 and ⩾2 mmol L-1. RESULTS: From the 7,795 patients found eligible during the study period, 7,447 patients were analysed. The median ∆Lact of our patients was 0.6 (0.3-1) mmol L-1. Most of the studied patients (65.9%) exhibited a ∆Lact between 0.1 and 0.9 mmol L-1. A concentration-dependent relationship was observed between ∆Lact and intensive care unit morbidity and 30-day mortality. After adjustment for co-variables, all ∆Lact > 0 was associated with an increase in overall intensive care unit morbidity. An independent relationship was also found between ∆Lact and 30-day mortality as of a 1 mmol L-1 increase. CONCLUSION: Our results suggest that ∆Lact is associated with poor short-term outcomes in adult cardiac surgical patients.

Feasibility of Automated Propofol Sedation for Transcatheter Aortic Valve Implantation: A Pilot Study.

BACKGROUND: Recently, several trials have shown that closed-loop sedation is feasible. No study has used automated sedation in extremely frail patients, such as those scheduled for transcatheter aortic valve implantation (TAVI). We developed and tested a novel automated sedation system for this kind of population and surgery. The system integrates a decision support system that detects respiratory and hemodynamic events via smart alarms, which provide pertinent/related clinical suggestions and treatment options. The main objective was the feasibility of closed-loop sedation, defined as successful automated sedation without manual override. Secondary qualitative observations were clinical and controller performance. METHODS: Twenty patients scheduled for elective TAVI were enrolled. Sedation was administered via a closed-loop delivery system designed for propofol. The clinical performance of sedation was the efficacy to maintain a bispectral index (BIS) of 65. To evaluate the sedation performance, BIS values were stratified into 4 categories: excellent, very good, good, and inadequate sedation control, defined as BIS values within 10%, ranging from 11% to 20%, ranging from 21% to 30%, or >30% from the target value, respectively. The controller performance was calculated using Varvel parameters. Critical respiratory and hemodynamic events were documented. The former was defined as peripheral oxygen saturation <92% and/or respiratory rate <8/min, whereas the latter was considered a mean arterial pressure <60 mm Hg and/or heart rate <40 bpm. RESULTS: Automated sedation was successful in 19 patients undergoing TAVI. One patient was excluded from the final analysis because of conversion to general anesthesia. The secondary observations revealed that the clinical performance allowed an excellent to good control during 69% (99% confidence interval, 53%-77%; interquartile range, 59%-79%) of the sedation time. Fifteen patients presented critical respiratory episodes, with a median of 3 events per hour of sedation. Six patients presented critical hemodynamic episodes, with a median of 2 events per hour of procedure. CONCLUSIONS: The automated closed-loop sedation system tested could be used successfully for patients scheduled for a TAVI procedure. The results showed a satisfactory clinical performance of sedation control.

A novel system for automated propofol sedation: hybrid sedation system (HSS).

Closed-loop systems for propofol have been demonstrated to be safe and reliable for general anesthesia. However, no study has been conducted using a closed-loop system specifically designed for sedation in patients under spinal anesthesia. We developed an automatic anesthesia sedation system that allows for closed-loop delivery of propofol for sedation integrating a decision support system, called the hybrid sedation system (HSS). The objective of this study is to compare this system with standard practice. One hundred fifty patients were enrolled and randomly assigned to two groups: HSS-Group (N = 75), in which propofol was administered using a closed-loop system; Control Group (N = 75), in which propofol was delivered manually. The clinical performance of the propofol sedation control is defined as efficacy to maintain bispectral index (BIS) near 65. The clinical control was called 'Excellent', 'Good', 'Poor' and 'Inadequate' with BIS values within 10 %, from 11 to 20 %, 21 to 30 %, or greater than 30 % of the BIS target of 65, respectively. The controller performance was evaluated using Varvel's parameters. Data are presented as mean ± standard deviation, groups were compared using t test or Chi square test, P < 0.05. Clinical performance of sedation showed 'Excellent' control in the HSS-group for a significantly longer period of time (49 vs. 26 % in the control group, P < 0.0001). 'Poor' and 'Inadequate' sedation was significantly shorter in the HSS Group compared to the Control Group (11 and 10 % vs. 20 and 18 %, respectively, P < 0.0001). The novel, closed-loop system for propofol sedation showed better maintenance of the target BIS value compared to manual administration.

The Feasibility of a Completely Automated Total IV Anesthesia Drug Delivery System for Cardiac Surgery.

BACKGROUND: In this pilot study, we tested a novel automatic anesthesia system for closed-loop administration of IV anesthesia drugs for cardiac surgical procedures with cardiopulmonary bypass. This anesthesia drug delivery robot integrates all 3 components of general anesthesia: hypnosis, analgesia, and muscle relaxation. METHODS: Twenty patients scheduled for elective cardiac surgery with cardiopulmonary bypass were enrolled. Propofol, remifentanil, and rocuronium were administered using closed-loop feedback control. The main objective was the feasibility of closed-loop anesthesia defined as successful automated cardiac anesthesia without manual override by the attending anesthesiologist. Secondary qualitative observations were clinical and controller performances. The clinical performance of hypnosis control was the efficacy to maintain a bispectral index (BIS) of 45. To evaluate the hypnosis performance, BIS values were stratified into 4 categories: "excellent," "good," "poor," and "inadequate" hypnosis control defined as BIS values within 10%, ranging from 11% to 20%, ranging from 21% to 30%, or >30% of the target value, respectively. The clinical performance of analgesia was the efficacy to maintain NociMap values close to 0. The analgesia performance was assessed classifying the NociMap values in 3 pain control groups: -33 to +33 representing excellent pain control, -34 to -66 and +34 to +66 representing good pain control, and -67 to -100 and +67 to +100 representing insufficient pain control. The controller performance was calculated using the Varvel parameters. RESULTS: Robotic anesthesia was successful in 16 patients, which is equivalent to 80% (97.5% confidence interval [CI], 53%-95%) of the patients undergoing cardiac surgery. Four patients were excluded from the final analysis because of technical problems with the automated anesthesia delivery system. The secondary qualitative observations revealed that the clinical performance of hypnosis allowed an excellent and good control during 70% (97.5% CI, 63%-76%) of maintenance time and an insufficient clinical performance of analgesia for only 3% (97.5% CI, 1%-6%) of maintenance time. CONCLUSIONS: The completely automated closed-loop system tested in this investigation could be used successfully and safely for cardiac surgery necessitating cardiopulmonary bypass. The results of the present trial showed satisfactory clinical performance of anesthesia control.

Impact of age on anaesthesiologists' competence: A narrative review.

The international anaesthesia community is getting older, in line with trends worldwide, and as men and women age there is the risk that psychophysiological decline could have an impact on clinical practice. Impairment of technical and nontechnical skills could have a negative impact on patients' safety and outcomes. The ageing process may not necessarily go hand-in-hand with a predictable pattern of decreased competence as not all aspects of functional decline are affected at the same rate and to the same extent. The development of simulation has provided a means of detecting and perhaps reversing the decline in ability associated with age. The introduction of recertification based on an assessment of competence at simulation sessions could play a crucial role in maintaining a high standard of patient care and an appropriate level of patient safety.

Association of Robotic Totally Endoscopic Coronary Artery Bypass Graft Surgery Associated With a Preliminary Cardiac Enhanced Recovery After Surgery Program: A Retrospective Analysis.

OBJECTIVES: The robotic totally endoscopic coronary artery bypass graft (TECAB) surgery reduces patients' recovery time. The present trial investigated the feasibility and safety of an initial enhanced recovery after surgery (ERAS) path for patients undergoing robotic beating-heart TECAB and compared it with both conventional surgery and traditional perioperative care. It was hypothesized that the preliminary ERAS pathway associated with a beating-heart TECAB procedure could have a synergistic effect on postoperative patient care. DESIGN: Observational retrospective study. SETTING: University hospital. PARTICIPANTS: Patients scheduled for coronary artery bypass graft and undergoing robotic beating-heart TECAB (n = 38) were compared with those undergoing standard surgery and perioperative care (n = 33). The outcomes were the possibility of tracheal extubation at the end of the surgery and the incidence of postoperative complications. MEASUREMENTS AND MAIN RESULTS: The main comorbidities were similar between the 2 groups. Extubation on the operating table in the TECAB group was possible in all cases without requiring prompt endotracheal tube reinsertion. The proportion of patients transfused was significantly lower in the TECAB group (p = 0.009). In addition, the duration of intensive care unit and hospital stay were reduced significantly by 24 hours and by 4 days, respectively, in the TECAB group compared with the standard group (p< 0.05). CONCLUSIONS: The present results suggested that a program coupling a beating-heart TECAB with a preliminary ERAS path for patients requiring a single coronary revascularization is feasible and safe. This approach could reduce postoperative mechanical ventilation time, transfusion rate, and both intensive care unit and hospital stay.

Use of a decision support system improves the management of hemodynamic and respiratory events in orthopedic patients under propofol sedation and spinal analgesia: a randomized trial.

Decision support systems (DSSs) have been successfully implemented into clinical practice offering clinical suggestions and treatment options with excellent results in various clinical settings. Although their results appeared promising, showing that DSSs can increase anesthesiologists' vigilance and patient safety during surgery, DSSs have never been used before to help anesthesiologists in identifying critical events in patients under spinal analgesia with sedation. We have developed and clinically evaluated a DSS for this specific task. The DSS was developed with the ability to indicate respiratory and hemodynamic critical events via audio-visual alarms and give decisional aid. Critical respiratory events were defined as SpO2 <92 % and/or respiratory rate <8/min. Critical hemodynamic events were defined as mean arterial pressure (MAP) <60 mmHg and/or heart rate <40 bpm. The objective of this trial was to determine the duration to detect and treat these critical events with the help of the DSS (DSS Group) compared with a standard Control Group where the system was not in place. One hundred and fifty orthopedic patients undergoing spinal analgesia with propofol sedation were enrolled in this randomized control trial, 75 each group. All respiratory and hemodynamic critical events were detected in the DSS Group, while in the Control Group 26 % of the events were not detected.The delay to detect and treat critical events was significantly shorter (P < 0.0001) in the DSS Group at 9.1 ± 3.6 s, whereas 27.5 ± 18.9 s were necessary to identify them in the Control Group. There were no significant differences in physiological parameters in the two groups during surgery. The number of critical events/h occurring and the duration of surgery were similar in both groups. The number of hypoxemia episodes was significantly less (P = 0.036) in the DSS group (0.7 ± 1.0 vs. 1.4 ± 2.2 for the Control Group). The DSS tested in this trial could help the clinician to detect and treat critical events more efficiently and in a shorter length of time.

Technical communication: First robotic ultrasound-guided nerve blocks in humans using the Magellan system.

BACKGROUND: Ultrasound-guided nerve blocks are becoming a standard of modern anesthesia. We developed a robotic system, Magellan, to perform nerve blocks using a remote control center. METHODS: Thirteen patients were enrolled in this pilot study. The Magellan system consists of 3 main components: a joystick, a robotic arm, and a software control system. The joystick allows simulation of wrist or arm movements of the proceduralist. After localization of the sciatic nerve, 35 mL of bupivacaine 0.25% was injected. The success rate of sciatic nerve blocks and block performance times (performance time=interval of time from the start of the ultrasound search for the nerve to the end of the injection of the drug; robotic time=interval of time from the identification of the nerve to the end of the injection of the drug) were determined. Data are presented as median (25th, 75th; minimal, maximal) and categorical data. RESULTS: Eight men and 5 women aged 34 years were included in this study. Nerve blocks were successful in all patients. A successful attempt was defined as the introduction of the needle into the nerve sheath; motor or sensory block was not used to determine the success rate. The nerve performance time was 189 seconds (150, 233; 90, 305), whereas the robotic time was 164 seconds (121, 210; 73, 271). CONCLUSIONS: We present the first human testing of a robotic ultrasound-guided nerve block system. The success rate was 100%. The total performance time was approximately 3 minutes to 4 minutes.

Preoperative Fibrinogen Level and Bleeding in Liver Transplantation for End-stage Liver Disease: A Cohort Study.

BACKGROUND: Liver transplantation is a high-risk surgery associated with important perioperative bleeding and transfusion needs. Uncertainties remain on the association between preoperative fibrinogen level and bleeding in this population. METHODS: We conducted a cohort study that included all consecutive adult patients undergoing a liver transplantation for end-stage liver disease in 1 center. We analyzed the association between the preoperative fibrinogen level and bleeding-related outcomes. Our primary outcome was intraoperative blood loss, and our secondary outcomes were estimated perioperative blood loss, intraoperative and perioperative red blood cell transfusions, reinterventions for bleeding and 1-y graft and patient survival. We estimated linear regression models and marginal risk models adjusted for all important potential confounders. We used restricted cubic splines to explore potential nonlinear associations and reported dose-response curves. RESULTS: We included 613 patients. We observed that a lower fibrinogen level was associated with a higher intraoperative blood loss, a higher estimated perioperative blood loss and a higher risk of intraoperative and perioperative red blood cell transfusions (nonlinear effects). Based on an exploratory analysis of the dose-response curves, these effects were observed below a threshold value of 3 g/L for these outcomes. We did not observe any association between preoperative fibrinogen level and reinterventions, 1-y graft survival or 1-y patient survival. CONCLUSIONS: This study suggests that a lower fibrinogen level is associated with bleeding in liver transplantation. The present results may help improving the selection of patients for further studies on preoperative fibrinogen administration in liver transplant recipients with end-stage liver disease.

A Medicoeconomic Evaluation of a Telehealth Platform for Elective Outpatient Surgeries: Protocol for a Randomized Controlled Trial.

BACKGROUND: The number of elective outpatient surgeries in Canada has increased markedly in the last 10 years. However, unanticipated cancellations on the day of surgery and adverse postoperative events are frequent. Modern technologies have been shown to be of great help in the medical field in improving patient care. Thus, it is likely that dedicated technologies could also significantly improve surgical outpatients' pathways. Therefore, the department of anesthesiology at the University of Montreal Medical Center, in collaboration with LeoMed, a telemedicine platform, has developed a telehealth solution to offer more efficient perioperative support and follow-up for patients undergoing ambulatory surgery. OBJECTIVE: The objective is to evaluate the medicoeconomic benefit of a dedicated perioperative telehealth platform for patients undergoing day surgery. Our hypothesis is that this dedicated telecare solution will allow more efficient patient care, which will reduce all types of medical costs related to day surgery pathways. METHODS: This study is a single-center, single-blinded, 2-group randomized controlled trial. One thousand patients aged over 18 years with internet access who are scheduled to undergo ambulatory surgery will be enrolled and randomized either to follow a perioperative path that includes a patient-tailored perioperative digital app via the LeoMed telecare platform for 1 month or to follow the standard of care, which does not offer personalized digital support. The primary outcome will be to evaluate the cost-effectiveness of the telecare platform, assessing direct costs from factors such as unanticipated cancellations on the day of surgery due to preoperative instructions not being followed, calls to the local health information line, calls to the provincial health information line, emergency department consultations, unplanned readmissions, or medical visits for problems related to the surgical procedure within the first 30 days after the intervention. The secondary outcome will be to evaluate cost utility using a questionnaire assessing quality-adjusted life years. A blinded independent research team will analyze outcomes. All data will be analyzed according to the intention-to-treat principle. A sample size of 500 subjects in each group was calculated to detect a 21% reduction in postoperative complications with a power of 90%. This study has been approved by the ethics board of Centre hospitalier de l'Université de Montréal (University of Montreal Health Centre). No employee of LeoMed was involved in the study conception, and none will be involved in either data collection or analysis. RESULTS: Results of this trial will be useful to determine the economic benefit of a telecare platform specifically developed for surgical outpatient pathways. CONCLUSIONS: We believe that the deployment of a dedicated perioperative telehealth app will lead to better patient care and fewer postoperative complications, which will lower all types of costs related to surgical outpatient care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04948632; https://ClinicalTrials.gov/ct2/show/NCT04948632. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/44006.

The Kepler intubation system.

Our goal in this study was to develop a robotic intubation system and to conduct a feasibility pilot study on the use of a robotic intubation system for endotracheal intubations. The Kepler Intubation System was developed, consisting of a remote control center (joystick and intubation cockpit) linked to a standard videolaryngoscope via a robotic arm. Ninety intubations were performed by the Kepler Intubation System on an airway trainer mannequin by a single operator. The first group of 30 intubations was performed with the operator in direct view of the mannequin (direct view group). The second group of 30 intubations was performed with the operator unable to see the mannequin (indirect view group). Thirty semiautomated intubations were also performed during which the robotic system replayed a trace of a previously recorded intubation maneuver (semiautomated group). First-attempt success rates and intubation times for each trial were recorded. Trends were analyzed using linear regression. Data are presented as mean (SD). All intubations were successful at first attempt. The mean intubation times were 46 (18) seconds, 51 (19) seconds, and 41 (1) seconds for the direct view, indirect view, and semiautomated group, respectively. Both the direct and indirect view groups had a negative slope, denoting that each successive trial required less time. The semiautomated group had a slope of 0 and a low SD of 1 second, illustrating the high reproducibility of automated intubations. We concluded that a robotic intubation system has been developed that can allow remote intubations within 40 to 60 seconds.