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The use of perioperative ECMO in lung transplantation helps overcome the unforeseen hemodynamic and respiratory instabilities that may occur during this type of surgery. However, no clear criteria are defined to predict the necessity of its application. Being able to anticipate the necessity for perioperative ECMO could enhance patient management, by preemptively avoiding unplanned ECMO and its associated complications. Therefore, we aim to assess whether criteria derived from preoperative echocardiography and right heart catheterization can effectively predict the necessity for ECMO support during lung transplantation. A total of 102 lung transplantations (27% for Pulmonary Fibrosis, 50% for Chronic Obstructive Pulmonary Disease, 10% for Pulmonary arterial hypertension and 13% for Cystic Fibrosis), performed at our center between January 2016 and December 2022, were retrospectively analyzed. Preoperative echocardiographies were reviewed, and qualitative and quantitative criteria were collected, alongside data from pre/perioperative right heart catheterization. Out of the total, 21 lung transplantations were performed under ECMO at our center. Our findings reveal that qualitative criteria derived from echocardiography, such as the presence of Right Ventricular Dysfunction (RVD) or moderate Tricuspid Regurgitation (mTR) are highly associated with the need for perioperative ECMO. In addition, various echocardiographic parameters, including Right Ventricle End-Diastolic Diameter (RVEDD), Tricuspid Annular Plane Systolic Excursion (TAPSE), Pulmonary Velocity Acceleration Time (PVAT), as well as values from perioperative right heart catheterization, such as systolic pulmonary arterial pressure (PAPs) and mean pulmonary arterial pressure (PAPm), were observed to be significantly correlated with the requirement for perioperative ECMO. Using Youden index and logistic regression, we established optimal cut-off values for each of these variables, as well as odds ratios, as indicated in the following table. Our study showed that we could identify patients at risk for unplanned ECMO during lung transplantation using criteria derived from preoperative echocardiography and perioperative right heart catheterization. These at-risk patients could gain from a preventive approach which could involve, for example, a preemptive introduction of ECMO cannula guides. [ABSTRACT FROM AUTHOR]

Cardiac surgery influences respiratory morbidity through multiple mechanisms. In our institution, the anesthesia team uses classic ventilation strategies: reduction of FiO2 and tidal volume, with PEEP and recruitment maneuvers. Their effectiveness is evaluated by continuous measurement of arterial oxygen saturation. But Peep is usually kept between 5 and 8 due to cardiac condition. Optimization of ventilation could still be possible. We postulate that this recruitment potential could be evaluated with the measurement of compliance and calculation of the R/I ratio (described the first time in 2020 by L.Chen & L.Brochard). ARDS Patients with a ratio >0.5 are candidates for optimization of ventilation parameters and new recruitment maneuvers. The primary endpoint is to evaluate the potential for alveolar recruitment, in patients undergoing cardiac surgery, at 2 times of the intervention (after intubation, and after cardiopulmonary bypass (CPB), by collecting the values of pulmonary compliance and the R/I ratio. The secondary endpoint is to determine if there are statistically significant differences, in terms of respiratory and hemodynamic parameters during and after recruitment. This is a prospective and observational study with agreement of our ethics committee. The 25 patients studied (Left ventricular ejection fraction above 40 %) are undergoing simple cardiac surgery (valve replacement, valve plasty or coronary artery bypass grafting). Patients' perioperative data were recorded, to evaluate the recruitment potential (Post-intubation, and post-CPB). The R/I ratio is measured with the single breath method describe by L. Chen: Peep is set at 12 mmHg during 3 min (= recruitment maneuver). "Abruptly releasing PEEP (from 12 to 5 cm H2O) increases expired volume: the difference between this volume and the volume predicted by compliance at low PEEP estimated the recruited volume by PEEP. This recruited volume divided by the effective pressure change gave the compliance of the recruited lung; the ratio of this compliance to the compliance at low PEEP gave the recruitment-to-inflation ratio". A low ratio indicate surdistension. Preliminary results show significant differences with improvement of compliance 10 min after recruitment. The median R/I was 1.58 ± 0.67 before CPB and, 1.15 ± 0.64 after CPB indicating a potential for recruitment. P/F values did not show a statistically significant increase, which could reflect good pulmonary vasoconstriction in pulmonary atelectasis. Pulmonary atelectasis aren't detectable with the ratio pO2/FiO2. Recruitment maneuvers, with moderate PEEP, are well tolerated in our patients, with a normal left ventricle (LV) ejection fraction. In conclusion R/I ratio highlights a potential for recruitment in our cardiac surgery patients. This test is hemodynamically well tolerated and could differentiate patients who are candidates for an increase in PEEP. A larger study is needed to confirm these results. [ABSTRACT FROM AUTHOR]

The TOFscan is an acceleromyographic neuromuscular monitor that calculates and displays two measurements: first, a train-of-four (TOF) ratio, or ratio of the fourth twitch in the TOF-sequence, T4, and the first twitch, T1 (T4/T1). In addition, a second, modified ratio is displayed (T4/Tr), which refers to the ratio between T4 and a reference twitch (Tr), calculated as the mean value of the four twitches in a TOF-sequence [Tr = (T1 + T2 + T3 + T4)/4]. T4/Tr is calculated before establishment of neuromuscular block. This prospective observational study included 35 adult patients. NMB induced by a rocuronium bolus of 0.6 mg/kg was continuously monitored at the adductor pollicis with the TOFscan and both TOF-ratios were simultaneously assessed. Primary outcome was the comparison of recovery to a TOF-ratio ≥ 0.9 calculated as T4/T1 and T4/Tr. The first value of the T4/T1 ≥ 90% was 90.9 (1.1) % and the simultaneously calculated T4/Tr was 69.6 (9.3) %, P < 0.001. The first value of the T4/Tr ≥ 90% was 90.5 (1.1) %, the simultaneously T4/T1 was 97.3 (2.5) %, P < 0.001. Time from injection of rocuronium to a TOF-ratio ≥ 90% was 56.2 ± 17.1 min for the T4/T1 and 65.3 ± 19.3 min for the T4/Tr, P < 0.001. During onset, a TOF ratio ≤ 20% was reached 145.5 (50.5) s after rocuronium when considering T4/T1, and 114.5 (45) s with the T4/Tr, P < 0.001. The present study shows the limitations of the usually determined acceleromyographic TOF ratio (T4/T1) in determining adequate neuromuscular recovery. The T4/T1 ratio significantly overestimates recovery compared with the T4/Tr ratio. Clinical decisions of adequate neuromuscular recovery based on the new T4/Tr ratio may reduce the incidence of residual paralysis and improve patient safety. [ABSTRACT FROM AUTHOR]

Background: Heterogeneity in microvascular perfusion is associated with impaired tissue oxygenation. We hypothesized that cardiac surgery with or without cardiopulmonary bypass (CPB) could induce microvascular alterations. Methods: We used an orthogonal polarization spectral imaging technique to evaluate the sublingual microcirculation in patients undergoing cardiac surgery with (n = 9) or without (n = 6) CPB. We also included, as a control group, 7 patients undergoing thyroidectomy with the same anesthetic procedure. Hemodynamic and microcirculatory variables were obtained the day before surgery, after induction of anesthesia, during CPB, on admission to the intensive care unit or the recovery room, and 6 and 24 hours after the end of the surgical procedure. Data are presented as median (25th to 75th percentile). Results: No differences in hemodynamic variables were observed between the two cardiac surgery groups. The proportion of perfused vessels was similar in all three groups at baseline (89% [87% to 90%]), and decreased similarly after induction of anesthesia to 71% (69% to 74%). It decreased further during CPB to 53% (50% to 56%). On admission to the intensive care unit or recovery room, alterations were more severe in CPB than in off-pump patients (60% [59% to 62%] versus 64% [61% to 65%]; p = 0.03), whereas they had already normalized in thyroidectomy patients (89% [86% to 90%]; p = 0.0005 versus cardiac surgery). In both cardiac surgery groups these microcirculatory alterations decreased with time, but persisted at 24 hours. The severity of microvascular alterations correlated with peak lactate levels after cardiac surgery (y = 11.5 − 0.15x; r 2 = 0.65; p < 0.05). Conclusions: Microcirculatory alterations are observed in cardiac surgery patients whether or not CPB is used. Anesthesia contributes to these alterations, but its effects are transient. [Copyright &y& Elsevier]

Objective: Auditory information presented during anesthesia can activate memory. Surgical stimulation may enhance memory formation. The authors'' hypothesis is that implicit memory processing is not preserved during unconsciousness, even in the presence of a surgical stimulus. Design: A double-blind randomized controlled trial. Setting: A single-institution, university hospital. Participants: Thirty-eight adults undergoing cardiac surgery. Interventions: Patients were randomized to continuously hear either disc A or B during surgery. On each disc, 20 different words were recorded. Measurements and Main Results: Implicit and explicit memory were tested. The study design was that each group served as a control for the other. The responses from both groups on both lists allowed the authors to compare the likeliness of correctly identifying the words from a list whether it was heard while under anesthesia or not. During the interview, no patient had explicit recall as investigated by the free recall test, and no one reported dreaming. As for implicit memory processing, the difference between the mean rate of correct answers on the word-stem completion test for the disc the patients heard (3.42% for disc A and 13.15% for disc B) or did not hear (3.15% for disc A and 14.73% for disc B) was not statistically significant (p = 0.95 for A and p = 0.42 for B). Conclusions: Explicit and implicit memory were not detectable in patients anesthetized with an effect-site target-controlled infusion of propofol and remifentanil with bispectral index monitoring. These results suggest that there is no memory processing under anesthesia in the surgical setting. [Copyright &y& Elsevier]

Objective: Pupillary reflex dilation (PRD) secondary to noxious stimulation accurately predicts sensory block during combined lumbar epidural/general anesthesia. Therefore, the adequacy of PRD-guided thoracic epidural infusion during general anesthesia for thoracotomy was studied. Design: Prospective study. Setting: University hospital. Participants: Thirteen patients undergoing thoracotomy. Interventions: An epidural catheter was placed at the T3-T4 level with initial infusion rate of 5 mL/h of ropivacaine 0.5%. Propofol/remifentanil target-controlled infusion was used for induction and maintenance of general anesthesia. Remifentanil effect site concentration was maintained constant at 0.5 ng/mL during surgery. By using a portable pupillometer, PRD secondary to tetanic stimulation of the C8, T2, and T4 segments were evaluated. Ropivacaine flow rate was adapted half hourly, according to PRD testing and a predefined algorithm. At the end of surgery, PRD was tested in the 3 investigated segments, and general anesthesia was stopped. After emergence, these zones were tested for their sensitivity to cold. Pain was evaluated by using the visual analog scale. Results: Pain scores were <3 of 10 in 84.6% of the patients. Mean PRD was 0.9 ± 0.6 mm in unblocked levels versus 0.2 ± 0.5 mm in blocked segments (p = 0.02). PRD ≥ 0.5 mm was predictive of incomplete block (sensitivity 76%, specificity 79%, and positive predictive value 86%). PRD ≥ 1 mm was highly predictive of inadequate block (sensitivity 73%, specificity 91%, and positive predictive value 94%). Conclusion: PRD-guided continuous thoracic epidural analgesia under low-dose remifentanil/propofol anesthesia is feasible and ensures good postoperative analgesia. [Copyright &y& Elsevier]