Effect of a comfort scale compared with a pain numerical rate scale on opioids consumption in postanaesthesia care unit: the COMFORT study.

BACKGROUND: The way that pain is assessed in the PACU could impact on postoperative pain and analgesic consumption. However, there is currently no evidence to support this speculation. The authors hypothesised that using a comfort scale reduces postoperative opioid consumption when compared with a standard numerical rating scale (NRS) to evaluate pain in the PACU. METHODS: In this cluster-randomised trial, patients were assessed using either a comfort scale (comfort group) or a pain NRS (NRS group). The primary outcome was the opioid consumption in the PACU. The main secondary outcomes were postoperative pain, nausea and vomiting, length of stay in the PACU, and satisfaction. RESULTS: Of 885 randomised patients, 860 were included in the analysis. Opioid consumption in the PACU was comparable in the comfort and NRS groups (median [interquartile range [IQR] 0 (0-5) vs 0 (0-6); P=0.2436), irrespective of the type of surgical procedure. The majority of patients did not need any postoperative opioid (59% in the comfort group and 56% in the NRS group, P=0.2260). There was no difference in postoperative pain, nausea and vomiting, time to reach an Aldrete score ≥9 after extubation, and global satisfaction. CONCLUSIONS: Using a comfort scale to assess pain in the PACU did not spare any opioid compared with use of a standard NRS. Further studies focusing on patients at risk of increased postoperative opioid consumption are necessary. CLINICAL TRIAL REGISTRATION: NCT05234216.

Knowledge-based, computerized, patient clinical decision support system for perioperative pain, nausea and constipation management: a clinical feasibility study.

Opioid administration is particularly challenging in the perioperative period. Computerized-based Clinical Decision Support Systems (CDSS) are a promising innovation that might improve perioperative pain control. We report the development and feasibility validation of a knowledge-based CDSS aiming at optimizing the management of perioperative pain, postoperative nausea and vomiting (PONV), and laxative medications. This novel CDSS uses patient adaptive testing through a smartphone display, literature-based rules, and individual medical prescriptions to produce direct medical advice for the patient user. Our objective was to test the feasibility of the clinical use of our CDSS in the perioperative setting. This was a prospective single arm, single center, cohort study conducted in Strasbourg University Hospital. The primary outcome was the agreement between the recommendation provided by the experimental device and the recommendation provided by study personnel who interpreted the same care algorithm (control). Thirty-seven patients were included in the study of which 30 (81%) used the experimental device. Agreement between these two care recommendations (computer driven vs. clinician driven) was observed in 51 out 54 uses of the device (94.2% [95% CI 85.9-98.4%]). The agreement level had a probability of 86.6% to exceed the 90% clinically relevant agreement threshold. The knowledge-based, patient CDSS we developed was feasible at providing recommendations for the treatment of pain, PONV and constipation in a perioperative clinical setting.Trial registration number & date The study protocol was registered in ClinicalTrial.gov before enrollment began (NCT05707247 on January 26th, 2023).

Early perioperative quality of recovery after hip and knee arthroplasty: a retrospective comparative cohort study.

PURPOSE: Increasing our knowledge about postoperative global Quality-Of-Recovery (QoR) after THA and TKA is important to improve perioperative medicine, in particular for preoperative patient information and benchmarking of postoperative patient status. METHODS: This study is a single centre, retrospective cohort study of prospectively collected data, conducted in Strasbourg University Hospital, Strasbourg, France. The main outcome was the modified French version of the QoR-15 (mQoR-15F) score monitored preoperatively, at postoperative day one, three, 14 and 28. We questioned the hypothesis: would THA and TKA recovery patterns differ and would postoperative health status eventually overreach the preoperative reference? RESULTS: The mQoR-15F was statistically higher in the THA group compared to the TKA group in POD 1 and 28 (112 ± 17 vs. 107 ± 17; p < 0.01 and 131 ± 12 vs. 127 ± 15; p = 0.02, respectively). The mean postoperative time delay to reach preoperative mQoR-15F was seven and 16 days for THA and TKA patients, respectively. CONCLUSION: Early postoperative health status after THA and TKA differs significantly; TKA being associated with a larger early decrease of global health status compared to THA. Both THA and TKA groups global health status overreached preoperative levels after one and two weeks postoperatively. These surgery-specific recovery profiles may favor improved patient information to steer advised operative decision and set specific recovery goals as part of enhanced recovery pathways.

Bayesian predictive probabilities: a good way to monitor clinical trials.

BACKGROUND: Bayesian methods, with the predictive probability (PredP), allow multiple interim analyses with interim posterior probability (PostP) computation, without the need to correct for multiple looks at the data. The objective of this paper was to illustrate the use of PredP by simulating a sequential analysis of a clinical trial. METHODS: We used data from the Laryngobloc trial that planned to include 480 patients to demonstrate the equivalence of success between a laryngoscopy performed with the Laryngobloc® device and a control device. A crossover Bayesian design was used. The success rates of the two laryngoscopy devices were compared. Interim analyses, computed from random numbers of subjects, were simulated. RESULTS: The PostP of equivalence rapidly reached the predefined bound of 0.95. The PredP computed with an equivalence margin of 10% reached the efficacy bound between 352 and 409 of the 480 included patients. If a frequentist analysis had been made on the basis of 217 out of 480 subjects, the study would have been prematurely stopped for equivalence. The PredP indicated that this result was nonetheless unstable and that the equivalence was, thus far, not guaranteed. CONCLUSIONS: Based on these interim analyses, we can conclude with a sufficiently high probability that the equivalence would have been met on the primary outcome before the predetermined end of this particular trial. If a Bayesian approach using PredP had been used, it would have allowed an early termination of the trial by reducing the calculated sample size by 15-20%.

Effects of Warmed and Humidified CO2 Surgical Site Insufflation in a Novel Experimental Model of Magnetic Compression Colonic Anastomosis.

Background. Pneumoperitoneum insufflation with warmed and humidified carbon dioxide (WH-CO2) can prevent heat loss and increase tissue oxygenation. We evaluated the impact of localized WH-CO2 insufflation on the anastomotic healing process. Methods. Sixty male Wistar rats were randomized: Group 1 (control, n = 12), Group 2 (cold and dry CO2, CD-CO2, n = 24), and Group 3 (WH-CO2, n = 24). A magnetic compression side-to-side colonic anastomosis was performed under 60-minute local abdominal CO2 flow insufflation. Animal temperature was recorded. IL-1, IL-6, and CRP levels were assessed before and after insufflation and on postoperative day (POD) 7 and POD 10. Endoscopic follow-up was performed on POD 7 and POD 10. A burst pressure (BP) test of the specimen was performed on POD 10, and histopathological analysis was then performed. Metabolomics of the anastomotic site was determined. Results. Seven rats (5 CD-CO2 group, 1 WH-CO2 group, and 1 control group) died during the survival period. Necropsies revealed intestinal occlusions (n = 2). One additional rat from the CD-CO2 group was sacrificed on POD 7 due to intestinal perforation. The postoperative course was uneventful in the remaining cases. There was no difference in BP among the groups. Thermal monitoring confirmed that WH-CO2 insufflation was effective to reduce heat loss. IL-1 levels were statistically and significantly lower on POD 10 in the WH-CO2 group than the CD-CO2 group but not lower than the control group. CRP levels, histopathology, and metabolomics did not show any difference between the 3 groups. Conclusions. WH-CO2 was effective to preserve core temperature. However, it did not improve anastomotic healing.

Validation of the translated Quality of Recovery-15 questionnaire in a French-speaking population.

BACKGROUND: Quality of recovery is an important component of perioperative health status. The 15-item Quality of Recovery (QoR-15) scale is a validated multidimensional questionnaire that measures postoperative quality of recovery. The aim of this study was to translate and assess the psychometric properties of a French version of the QoR-15 scale (QoR-15F) to measure postoperative recovery in French-speaking patients. METHODS: After translation into French of the original English version of the QoR-15 scale, psychometric validation of the QoR-15F scale to measure postoperative quality of recovery was performed. This psychometric validation included validity, reliability, responsiveness, and feasibility. The QoR-15F scale was administered before operation and on Postoperative day 1 in French-speaking patients. Patient-perceived global recovery assessment was measured at Postoperative day 1 using a VAS. RESULTS: We enrolled 150 patients, and 144 completed the study protocol. The completion rate of administered questionnaires was 100%. Pearson (r) correlation between postoperative QoR-15F and the global recovery assessment by the patient was 0.60 (P<0.0001). As expected, there was a significant negative correlation between QoR-15F score and duration of surgery (r=-0.29; P<0.01), duration of PACU stay (r=-0.21; P=0.01), and duration of hospital stay (r=-0.34; P<0.01). Cronbach's alpha was 0.81, split-half alpha was 0.83, and the global test-retest intra-class coefficient was 0.98 (0.95-0.99). CONCLUSIONS: The QoR-15F is a valid and reliable tool to measure postoperative quality of recovery in French-speaking patients. The psychometric properties to measure postoperative quality of recovery were similar to the seminal English version. CLINICAL TRIAL REGISTRATION: NCT03578068.

Effect of Hydroxyethyl Starch vs Saline for Volume Replacement Therapy on Death or Postoperative Complications Among High-Risk Patients Undergoing Major Abdominal Surgery: The FLASH Randomized Clinical Trial.

Importance: It is not known if use of colloid solutions containing hydroxyethyl starch (HES) to correct for intravascular deficits in high-risk surgical patients is either effective or safe. Objective: To evaluate the effect of HES 130/0.4 compared with 0.9% saline for intravascular volume expansion on mortality and postoperative complications after major abdominal surgery. Design, Setting, and Participants: Multicenter, double-blind, parallel-group, randomized clinical trial of 775 adult patients at increased risk of postoperative kidney injury undergoing major abdominal surgery at 20 university hospitals in France from February 2016 to July 2018; final follow-up was in October 2018. Interventions: Patients were randomized to receive fluid containing either 6% HES 130/0.4 diluted in 0.9% saline (n = 389) or 0.9% saline alone (n = 386) in 250-mL boluses using an individualized hemodynamic algorithm during surgery and for up to 24 hours on the first postoperative day, defined as ending at 7:59 am the following day. Main Outcomes and Measures: The primary outcome was a composite of death or major postoperative complications at 14 days after surgery. Secondary outcomes included predefined postoperative complications within 14 days after surgery, durations of intensive care unit and hospital stays, and all-cause mortality at postoperative days 28 and 90. Results: Among 826 patients enrolled (mean age, 68 [SD, 7] years; 91 women [12%]), 775 (94%) completed the trial. The primary outcome occurred in 139 of 389 patients (36%) in the HES group and 125 of 386 patients (32%) in the saline group (difference, 3.3% [95% CI, -3.3% to 10.0%]; relative risk, 1.10 [95% CI, 0.91-1.34]; P = .33). Among 12 prespecified secondary outcomes reported, 11 showed no significant difference, but a statistically significant difference was found in median volume of study fluid administered on day 1: 1250 mL (interquartile range, 750-2000 mL) in the HES group and 1500 mL (interquartile range, 750-2150 mL) in the saline group (median difference, 250 mL [95% CI, 83-417 mL]; P = .006). At 28 days after surgery, 4.1% and 2.3% of patients had died in the HES and saline groups, respectively (difference, 1.8% [95% CI, -0.7% to 4.3%]; relative risk, 1.76 [95% CI, 0.79-3.94]; P = .17). Conclusions and Relevance: Among patients at risk of postoperative kidney injury undergoing major abdominal surgery, use of HES for volume replacement therapy compared with 0.9% saline resulted in no significant difference in a composite outcome of death or major postoperative complications within 14 days after surgery. These findings do not support the use of HES for volume replacement therapy in such patients. Trial Registration: ClinicalTrials.gov Identifier: NCT02502773.

Surgical Support for Severe COVID-19 Patients: A Retrospective Cohort Study in a French High-Density COVID-19 Cluster.

Background. The COVID-19 epidemic has resulted in a massive surge in the need for intensive care unit (ICU) care. To avoid being overwhelmed, hospitals had to adapt and support the ICU teams in structured ICU care including involving surgical teams. This work aims at describing the collaborative efforts between the ICU care team and the Surgical Task Force (STF) during a surge of ICU activity in a University Hospital in a French high-density COVID-19 cluster. Study Design. This retrospective single center study analyzed the STF workflow and the ICU population. The study included 55 patients hospitalized in our ICU, ICU-converted step-down units, and post-anesthesia care units. The primary measure was the global daily STF activity. The secondary measure was the daily activity for each of the 5 tasks accomplished by the STF. Results. The STF attempted 415 phone calls for 55 patients' families, 237 mobilizations of patients requiring prone positions, follow-up of 20 patients requiring medevac, and contribution to ethical discussion for 2 patients. The mean (SD) daily number of successful phones calls, ethical discussions, mobilizations of patients requiring prone positions and medevac follow-up were 18 (7), .1 (.4), 10 (7), and 2 (3), respectively. No actions for discharge summaries writing were required. The maximum number of daily mobilizations for patients requiring prone positions was 25. The maximum number of daily attempted phone calls and successful phone calls were 37 and 26, respectively. Conclusion. Surgeons' technical and nontechnical skills represented an effective support for ICU teams during the COVID-19 pandemic.

Trainability of Cricoid Pressure Force Application: A Simulation-Based Study.

BACKGROUND: Aspiration of gastric contents is a leading cause of airway management-related mortality during anesthesia practice. Cricoid pressure (CP) is widely used during rapid sequence induction to prevent aspiration. National guidelines for CP suggest a target force of 10 N before and 30 N after loss of consciousness. However, few studies have rigorously assessed whether clinicians can be trained to consistently achieve these levels of force. We hypothesized that clinicians can be trained effectively to deliver 10-30 N during application of CP. METHODS: Clinicians (attending anesthesiologist, anesthesiology residents, certified registered nurse anesthetists, or operating room nurses) applied CP on a Vernier force plate simulator with measurements taken at 4 time points over 60 seconds, 2 measurements before and 2 measurements after loss of consciousness. A successful cycle required all 4 time points to be within the target range (10 ± 5 and 30 ± 5 N, respectively). After baseline assessment (n = 100 clinicians), a subset of 40 participants volunteered for education on recommended force targets, underwent self-regulated practice, and then performed 30 1-minute cycles of high-frequency simulation analyzed by cumulative sum analysis to assess their change in performance. RESULTS: At baseline, 5 cycles (1.3% [confidence interval {CI}, 0.3%-2.50%]) out of 400 were successful. Performance improved after education and self-regulated practice (16% successful cycles [CI, 7.8%-25%]), and performance during the last 4 of 30 cycles was 45% (CI, 33%-58%). The odds of success increased over time (odds ratio, 1.1; P < .001). By cumulative sum analysis, however, no subject crossed the h0 line, indicating that no one achieved proficiency of the predefined target forces. CONCLUSIONS: At baseline, performance was poor at achieving target forces specified by national guidelines. Simulation-based training improved the success rate, but no participant achieved the predefined threshold for proficiency.

Efficacy of acupressure on quality of recovery after surgery: Randomised controlled trial.

BACKGROUND: Acupressure therapy is associated with favourable efficacies on postoperative nausea, pain and sleep disturbance, although the quality of the evidence is generally low. No randomised clinical trial has yet assessed the effect of acupressure on postoperative quality of recovery (QoR). OBJECTIVE: The objective was to study acupressure efficacy on patient-reported postoperative recovery. DESIGN: We conducted a single centre, three-group, blind, randomised controlled, pragmatic trial assessing acupressure therapy on the PC6, LI4 and HT7 acupoints. PATIENTS: Postoperative patients expected to stay in hospital at least 2 days after surgery. INTERVENTIONS: In the acupressure group, pressure was applied for 6 min (2 min per acupoint), three times a day after surgery for a maximum of 2 postoperative days during the hospital stay. In the sham group, extremely light touch was applied to the acupoints. The third group did not receive any touch. MAIN OUTCOME MEASURES: The primary outcome was the change in the QoR, using the QoR-15 questionnaire, between postoperative days 1 and 3. Key secondary outcomes included patients' satisfaction, postoperative nausea and vomiting, pain score and opioid (morphine equivalent) consumption. Assessors for the primary and secondary endpoints were blind to the group allocation. RESULTS: Overall, 163 patients were randomised (acupressure n=55, sham n=53, no intervention n=55). The mean (SD) postoperative change in QoR-15 did not differ statistically (P = 0.27) between the acupressure, sham and no intervention groups: 15.2 (17.8), 14.2 (21.9), 9.2 (21.7), respectively. Patient satisfaction (on a 0 to 10 scale) was statistically different (P = 0.01) among these three groups: 9.1 (1.5), 8.4 (1.6) and 8.2 (2.2), respectively. Changes in pain score and morphine equivalent consumption were not significantly different between the groups. CONCLUSION: Two days of postoperative acupressure therapy (up to six treatments) did not significantly improve patient QoR, postoperative nausea and vomiting, pain score or opioid consumption. Acupressure, however, was associated with improved patient satisfaction. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02762435.

Impact of valve-less vs. standard insufflation on pneumoperitoneum volume, inflammation, and peritoneal physiology in a laparoscopic sigmoid resection experimental model.

BACKGROUND: Standard insufflators compensate for intra-abdominal pressure variations with pressure spikes. Our aim was to evaluate the impact of a stable, low-pressure pneumoperitoneum induced by a valve-less insufflator, on working space, hemodynamics, inflammation, and peritoneal physiology, in a model of laparoscopic sigmoid resection. MATERIALS AND METHODS: Twelve pigs (47 ± 3.3 kg) were equipped for invasive hemodynamic monitoring and randomly assigned to Standard (n = 6) vs. valve-less (n = 6) insufflation. Animals were positioned in a 30° Trendelenburg on a CT scan bed. A low-pressure pneumoperitoneum (8 mmHg) was started and duration was set for 180 min. Abdominal CT scans were performed, under neuromuscular blockade, before, immediately after, and 1 and 3 h after insufflation. Pneumoperitoneum volumes were calculated on 3D reconstructed CT scans. After creation of a mesenteric window, capillary blood was obtained by puncturing the sigmoid serosa and local lactatemia (mmol/L) was measured using a handheld analyzer. Surgical resection was performed according to the level of lactates, in order to standardize bowel stump perfusion. IL-1 and IL-6 (ng/mL) were measured repeatedly. The peritoneum was sampled close to the surgical site and distantly for the oxygraphic assessment of mitochondrial respiration. A pathologist applied a semi-quantitative score to evaluate the anastomosis. RESULTS: Mean arterial pressure, pulse, body temperature, oximetry, systemic lactatemia, and local lactates were similar. IL-6 was lower in the valve-less group, reaching a statistically significant difference after 3 h of insufflation (64.85 ± 32.5 vs. 133.95 ± 59.73; p = 0.038) and 48 h (77.53 ± 68.4 vs. 190.74 ± 140.79; p = 0.029). Peritoneal mitochondrial respiration was significantly increased after the survival period, with no difference among the groups. The anastomoses in the valve-less group demonstrated a lower acute (p = 0.04) inflammatory infiltration. The mean anterior posterior thickness was slightly, yet significantly higher in the valve-less group, on all post-insufflation CT scans. CONCLUSIONS: Valve-less insufflation achieved a slightly higher working space and a lower systemic and localized inflammatory response in this experimental setting.

Precision real-time evaluation of bowel perfusion: accuracy of confocal endomicroscopy assessment of stoma in a controlled hemorrhagic shock model.

BACKGROUND AND AIMS: Confocal laser endomicroscopy (CLE) can provide real-time evaluation of bowel perfusion. We aimed to evaluate CLE perfusion imaging in a hemorrhagic shock model. MATERIALS AND METHODS: Five pigs were equipped to ensure hemodynamic monitoring. Three ileostomies per animal (total n = 15) were randomly created (T0). Blood was withdrawn targeting a mean arterial pressure of 40 mmHg (shock phase, T1), for 90 min. Infusion of Ringer's lactate was started and continued for 90 min (T2). At the different time points: (a) stomas' mucosa was scanned with CLE; (b) capillary lactates were measured on blood obtained by puncturing stomas' mucosa; and (c) full-thickness stomas' biopsies were sampled for histology, mitochondrial respiratory rate (V 0 = basal and V ADP = respiratory rate in excess of adenosine diphosphate), and levels of superoxide anion evaluation. Functional capillary density (FCD) was measured using ad hoc software. RESULTS: Confocal scanning provided consistent and specific imaging of bowel hypoperfusion at T1: vascular hyperpermeability (blurred and enlarged capillaries) and edema (enhanced visualization of the brush border due to increased intercellular spaces and fluorescein leakage). At the end of T2, there was an improved capillary flow. FCD-A index expressed statistically significant correlation with (1) stoma capillary lactates (p = 0.023); (2) systemic capillary lactates (p = 0.031); (3) inflammation pathology score (p = 0.048); (4) central venous pressure (p = 0.0043); and (5) pulmonary artery pressure (p = 0.01). Stoma capillary lactates (mmol/L) were significantly increased at T1 (8.81 ± 4.23; p < 0.0001) and at T2 (4.77 ± 3.13; p < 0.01) when compared to T0 inclusion values (1.86 ± 0.56). V 0 and V ADP (pmol O2/min/mg tissue) were both significantly decreased at T1 versus T0 (p < 0.007 and p < 0.01, respectively) and recovered by the end of reanimation (T2 vs. T0, p = n.s.). Mean O 2·- production (µmol/min/mg/dry tissue) increased at T1 and significantly decreased at T2. CONCLUSIONS: Confocal laser endomicroscopy (CLE) imaging could identify morphological signs congruent with biochemical markers of bowel perfusion and could be useful for assessment of stomas.

Comparative analysis of resuscitation using human serum albumin and crystalloids or 130/0.4 hydroxyethyl starch and crystalloids on skeletal muscle metabolic profile during experimental haemorrhagic shock in swine: A randomised experimental study.

BACKGROUND: Protection against acute skeletal muscle metabolic dysfunction and oxidative stress could be a therapeutic target in volume expansion for severely bleeding patients. OBJECTIVES: This experimental pilot study in swine aims at comparing 130/0.4 hydroxyethyl starch (HES) with 4% albumin along with crystalloid perfusion for first-line volume expansion in haemorrhagic shock with a particular emphasis on oxidative stress and muscular mitochondrial function. DESIGN: Randomised experimental study. SETTING: Digestive Cancer Research Institute Preclinical Laboratory, Strasbourg University Hospital, France, from February 2012 to June 2013. ANIMALS: Twenty large white pigs. INTERVENTION: Pressure-controlled haemorrhagic shock and volume resuscitation using either 4% human serum albumin or 130/0.4 HES along with crystalloid perfusion were performed in 20 large white pigs. MAIN OUTCOME MEASURES: Muscular biopsy of gastrocnemius muscle was performed for metabolomics screening, mitochondrial respiratory chain assessment and electron spin resonance reactive oxygen species production along with arterial and venous reactive oxygen species production at baseline, at the completion of shock, at 90 min and at 180 min after volume expansion. RESULTS: There was no difference between the two groups in measurements of skeletal muscle superoxide production. In a pooled analysis, there was a statistically significant decrease in gastrocnemius muscle creatine content from baseline to 90 min (P < 0.05) and 180 min (P < 0.05). Muscular lactate content and mitochondrial respiratory chain oxidative capacity remained constant at the respective time points. CONCLUSION: In this pilot experimental study in swine, during pressure-controlled haemorrhagic shock treated with either albumin or 130/0.4 HES in conjunction with crystalloid perfusion, skeletal muscle metabolic profile was unaltered. ETHICAL APPROVAL NUMBER: 38.2012.01.031.

Does the unexpected death of the manikin in a simulation maintain the participants' perceived self-efficacy? An observational prospective study with medical students.

BACKGROUND: The death of a simulated patient is controversial. Some educators feel that having a manikin die is prejudicial to learning; others feel it is a way of better preparing students for these situations. Perceived self-efficacy (PSE) reflects a person's perception of their ability to carry out a task. A high PSE is necessary to manage a task efficiently. In this study, we measured the impact of the death of a simulated patient on medical students' perceived self-efficacy concerning their ability to cope with a situation of cardiac arrest. METHODS: We carried out a single-centre, observational, prospective study. In group 1 (n = 27), pre-graduate medical students were warned of the possible death of the manikin; group 2 students were not warned (n = 29). The students' PSE was measured at the end of the simulated situation and after the debriefing. RESULTS: The PSE of the two groups was similar before the debriefing (p = 0.41). It had significantly progressed at the end of the debriefing (p < 0,001). No significant difference was noted between the 2 groups (p = 0.382). CONCLUSIONS: The simulated death of the manikin did not have a negative impact on the students' PSE, whether or not they had been warned of the possible occurrence of such an event. Our study helps defend the position which supports the inclusion of unexpected death of the manikin in a simulation setting.

Impact of nitrous oxide on the haemodynamic consequences of venous carbon dioxide embolism: An experimental study.

BACKGROUND: Nitrous oxide (N2O) is still considered an important component of general anaesthesia. However, should gas embolisation occur as result of carbon dioxide (CO2) pneumoperitoneum, N2O may compromise safety, as the consequences of a gas embolus consisting of a combination of CO2 and N2O may be more severe than CO2 alone. OBJECTIVE: This experimental study was designed to compare the cardiopulmonary consequences of gas embolisation with a N2O/CO2 mixture, or CO2 alone. DESIGN: Experimental study. SETTING: Research Institute Against Digestive Cancer laboratory, Strasbourg, France. ANIMALS: Seven Large-White pigs receiving standardised inhalation anaesthesia. INTERVENTIONS: Each animal, acting as its own control, was studied in two successive experimental conditions - intravenous gas injections of 2 ml kg of 100% CO2 and 2 ml kg of a gas mixture consisting of 10% N2O and 90% CO2. MAIN OUTCOMES MEASURES: Haemodynamic and ventilatory consequences of embolisation with the gases. RESULTS: We found that the haemodynamic (heart rate, mean arterial blood pressure, central venous pressure, mean pulmonary artery pressure, pulmonary artery occlusion pressure and transoesophageal echocardiography parameters) and ventilatory (arterial oxygen saturation, end-tidal CO2 concentration and mixed venous oxygen saturation) consequences of embolisation with either 100% CO2 or 10% N2O with 90% CO2 were similar. CONCLUSION: The findings of this study may alleviate concerns that the use of N2O, as a part of a balanced general anaesthesia technique, may have greater adverse consequences should embolisation of pneumoperitoneal gas containing N2O occur.

Metabolism-Guided Bowel Resection: Potential Role and Accuracy of Instant Capillary Lactates to Identify the Optimal Resection Site.

BACKGROUND: Strip-based handheld devices can measure lactatemia on capillary blood obtained by needle puncturing. We aimed to assess the kinetic of bowel capillary lactates, metabolomics profiling, and mitochondria respiratory rate in a prolonged model of bowel hypoperfusion. MATERIALS AND METHODS: In 6 pigs, a 3- to 4-cm ischemic segment was created in 6 small bowel loops (total = 36 loops) by clamping the vascular supply, for a duration of 1 to 6 hours. Hourly, 5 blood samples were obtained by puncturing the serosa, and lactates were measured using a handheld analyzer. Samples were made at the following regions of interest (ROIs): center of the ischemic area (1), proximal and distal clinical margins of resection (2a-2b), and vascularized zones (3a-3b). Every hour, surgical biopsies of ROIs were sampled. Activity of bowel mitochondria complexes was measured after 1, 3, and 5 hours of ischemia. Quantification of metabolites was performed on all samples (total N = 180). RESULTS: Capillary lactates were significantly higher at ROI 1 versus ROI 3ab at all time points. After 1 hour lactates at the margins were significantly higher than those at vascularized areas (P = .0095), showing a mismatch between visual assessment and actual perfusion status. From 2 to 6 hours, there was no difference in lactates between ROIs 2a-2b and 3a-3b. Maximal tissue respiration decreased significantly after 1 hour (ROI 1 vs ROI 3ab). Seven metabolites (lactate, glucose, aspartate, choline, creatine, taurine, and tyrosine) expressed significantly different evolutions between ROIs. CONCLUSIONS: Capillary lactates could help precisely estimate local bowel perfusion status.

Enhanced-reality video fluorescence: a real-time assessment of intestinal viability.

OBJECTIVE: Our aim was to evaluate a fluorescence-based enhanced-reality system to assess intestinal viability in a laparoscopic mesenteric ischemia model. MATERIALS AND METHODS: A small bowel loop was exposed, and 3 to 4 mesenteric vessels were clipped in 6 pigs. Indocyanine green (ICG) was administered intravenously 15 minutes later. The bowel was illuminated with an incoherent light source laparoscope (D-light-P, KarlStorz). The ICG fluorescence signal was analyzed with Ad Hoc imaging software (VR-RENDER), which provides a digital perfusion cartography that was superimposed to the intraoperative laparoscopic image [augmented reality (AR) synthesis]. Five regions of interest (ROIs) were marked under AR guidance (1, 2a-2b, 3a-3b corresponding to the ischemic, marginal, and vascularized zones, respectively). One hour later, capillary blood samples were obtained by puncturing the bowel serosa at the identified ROIs and lactates were measured using the EDGE analyzer. A surgical biopsy of each intestinal ROI was sent for mitochondrial respiratory rate assessment and for metabolites quantification. RESULTS: Mean capillary lactate levels were 3.98 (SD = 1.91) versus 1.05 (SD = 0.46) versus 0.74 (SD = 0.34) mmol/L at ROI 1 versus 2a-2b (P = 0.0001) versus 3a-3b (P = 0.0001), respectively. Mean maximal mitochondrial respiratory rate was 104.4 (±21.58) pmolO2/second/mg at the ROI 1 versus 191.1 ± 14.48 (2b, P = 0.03) versus 180.4 ± 16.71 (3a, P = 0.02) versus 199.2 ± 25.21 (3b, P = 0.02). Alanine, choline, ethanolamine, glucose, lactate, myoinositol, phosphocholine, sylloinositol, and valine showed statistically significant different concentrations between ischemic and nonischemic segments. CONCLUSIONS: Fluorescence-based AR may effectively detect the boundary between the ischemic and the vascularized zones in this experimental model.

Perioperative Patient Blood Management (excluding obstetrics): Guidelines from the French National Authority for Health.

The French National Authority for Health (HAS) recently issued guidelines for patient blood management (PBM) in surgical procedures. These recommendations are based on three usual pillars of PBM: optimizing red cell mass, minimizing blood loss and optimizing anemia tolerance. In the preoperative period, these guidelines recommend detecting anemia and iron deficiency and taking corrective measures well in advance of surgery, when possible, in case of surgery with moderate to high bleeding risk or known preoperative anemia. In the intraoperative period, the use of tranexamic acid and some surgical techniques are recommended to limit bleeding in case of high bleeding risk or in case of hemorrhage, and the use of cell salvage is recommended in some surgeries with a major risk of transfusion. In the postoperative period, the limitation of blood samples is recommended but the monitoring of postoperative anemia must be carried out and may lead to corrective measures (intravenous iron in particular) or more precise diagnostic assessment of this anemia. A "restrictive" transfusion threshold considering comorbidities and, most importantly, the tolerance of the patient is recommended postoperatively. The implementation of a strategy and a program for patient blood management is recommended throughout the perioperative period in healthcare establishments in order to reduce blood transfusion and length of stay. This article presents an English translation of the HAS recommendations and a summary of the rationale underlying these recommendations.