CACS, CCTA and mCAD-LT score in the pre-transplant assessment of coronary artery disease and the prediction of post-transplant cardiovascular events.

BACKGROUND: The optimal cardiovascular assessment of liver transplant (LT) candidates is unclear. We aimed to evaluate the performance of CT-based coronary tests (coronary artery calcium score [CACS] and coronary CT angiography [CCTA]) and a modification of the CAD-LT score (mCAD-LT, excluding family history of CAD) to diagnose significant coronary artery disease (CAD) before LT and predict the incidence of post-LT cardiovascular events (CVE). METHODS: We retrospectively analysed a single-centre cohort of LT candidates who underwent non-invasive tests; invasive coronary angiography (ICA) was performed depending on the results of non-invasive tests. mCAD-LT was calculated in all patients. RESULTS: Six-hundred-and-thirty-four LT candidates were assessed and 351 of them underwent LT. CACS, CCTA and ICA were performed in 245, 123 and 120 LT candidates, respectively. Significant CAD was found in 30% of patients undergoing ICA. The AUROCs of mCAD-LT (.722) and CCTA (.654) were significantly higher than that of CACS (.502) to predict the presence of significant CAD. Specificity of the tests ranged between 31% for CCTA and 53% for CACS. Among patients who underwent LT, CACS ≥ 400 and mCAD-LT were independently associated with the incidence of CVE; in patients who underwent CCTA before LT, significant CAD at CCTA also predicted post-LT CVE. CONCLUSION: In this cohort, mCAD-LT score and CT-based tests detect the presence of significant CAD in LT candidates, although they tend to overestimate it. Both mCAD-LT score and CT-based tests classify LT recipients according to their risk of post-LT CVE and can be used to improve post-LT risk mitigation.

Association between preoperative anemia optimization and major complications after non-cardiac surgery: a retrospective analysis.

BACKGROUND: Anemia is common in the preoperative setting and associated with increased postoperative complications and mortality. However, it is unclear if preoperative anemia optimization reduces postoperative complications. We aimed to assess the association between preoperative anemia optimization and a composite endpoint of major cardiovascular, renal, and pulmonary complications and all-cause mortality within 30 days after noncardiac surgery in adult patients. METHODS: In this retrospective analysis preoperative anemia was defined as hemoglobin concentration below 12.0 g.dl-1 in women and 13.0 g.dl-1 in men within 6 months before surgery. A propensity score-based generalized estimating equation analysis was used to determine the association between preoperative anemia optimization and the primary outcome. Moreover, mediation analysis was conducted to investigate whether intraoperative red blood cell transfusion or duration of intraoperative hypotension were mediators of the relation between anemia optimization and the primary outcome. RESULTS: Fifty-seven hundred anemia optimized, and 8721 non-optimized patients met study criteria. The proportion of patients having any component of the composite of major complications and all-cause mortality was 21.5% in the anemia-optimized versus 18.0% in the non-optimized, with confounder-adjusted odds ratio estimate of 0.99 (95% CI 0.86‒1.15) for anemia optimization versus non-optimization, p = 0.90. Intraoperative red blood cell transfusion had a minor mediation effect on the relationship between preoperative anemia optimization and the primary outcome, whereas duration of intraoperative hypotension was not found to be a mediator. CONCLUSION: Preoperative anemia optimization did not appear to be associated with a composite outcome of major in-hospital postoperative cardiovascular, renal, and pulmonary complications and all-cause in-hospital mortality.

Association between preoperative anemia optimization and major complications after non-cardiac surgery: a retrospective analysis

Abstract Background: Anemia is common in the preoperative setting and associated with increased postoperative complications and mortality. However, it is unclear if preoperative anemia optimization reduces postoperative complications. We aimed to assess the association between preoperative anemia optimization and a composite endpoint of major cardiovascular, renal, and pulmonary complications and all-cause mortality within 30 days after noncardiac surgery in adult patients. Methods: In this retrospective analysis preoperative anemia was defined as hemoglobin concentration below 12.0 g.dl−1 in women and 13.0 g.dl−1 in men within 6 months before surgery. A propensity score-based generalized estimating equation analysis was used to determine the association between preoperative anemia optimization and the primary outcome. Moreover, mediation analysis was conducted to investigate whether intraoperative red blood cell transfusion or duration of intraoperative hypotension were mediators of the relation between anemia optimization and the primary outcome. Results: Fifty-seven hundred anemia optimized, and 8721 non-optimized patients met study criteria. The proportion of patients having any component of the composite of major complications and all-cause mortality was 21.5% in the anemia-optimized versus 18.0% in the non-optimized, with confounder-adjusted odds ratio estimate of 0.99 (95% CI 0.86-1.15) for anemia optimization versus non-optimization, p = 0.90. Intraoperative red blood cell transfusion had a minor mediation effect on the relationship between preoperative anemia optimization and the primary outcome, whereas duration of intraoperative hypotension was not found to be a mediator. Conclusion: Preoperative anemia optimization did not appear to be associated with a composite outcome of major in-hospital postoperative cardiovascular, renal, and pulmonary complications and all-cause in-hospital mortality.

User Perceptions of Avatar-Based Patient Monitoring for Intensive Care Units: An International Exploratory Sequential Mixed-Methods Study.

Visual Patient Avatar ICU is an innovative approach to patient monitoring, enhancing the user's situation awareness in intensive care settings. It dynamically displays the patient's current vital signs using changes in color, shape, and animation. The technology can also indicate patient-inserted devices, such as arterial lines, central lines, and urinary catheters, along with their insertion locations. We conducted an international, multi-center study using a sequential qualitative-quantitative design to evaluate users' perception of Visual Patient Avatar ICU among physicians and nurses. Twenty-five nurses and twenty-five physicians from the ICU participated in the structured interviews. Forty of them completed the online survey. Overall, ICU professionals expressed a positive outlook on Visual Patient Avatar ICU. They described Visual Patient Avatar ICU as a simple and intuitive tool that improved information retention and facilitated problem identification. However, a subset of participants expressed concerns about potential information overload and a sense of incompleteness due to missing exact numerical values. These findings provide valuable insights into user perceptions of Visual Patient Avatar ICU and encourage further technology development before clinical implementation.

Early detection of deterioration in COVID-19 patients by continuous ward respiratory rate monitoring: a pilot prospective cohort study.

Background: Tachypnea is among the earliest signs of pulmonary decompensation. Contactless continuous respiratory rate monitoring might be useful in isolated COVID-19 patients admitted in wards. We therefore aimed to determine whether continuous monitoring of respiratory patterns in hospitalized patients with COVID-19 predicts subsequent need for increased respiratory support. Methods: Single-center pilot prospective cohort study in COVID-19 patients who were cared for in routine wards. COVID-19 patients who had at least one escalation of pulmonary management were matched to three non-escalated patients. Contactless respiratory monitoring was instituted after patients enrolled, and continued for 15 days unless hospital discharge, initiation of invasive mechanical ventilation, or death occurred. Clinicians were blinded to respiratory rate data from the continuous monitor. The exposures were respiratory features over rolling periods of 30 min, 24 h, and 72 h before respiratory care escalation. The primary outcome was a subsequent escalation in ventilatory support beyond a Venturi mask. Results: Among 125 included patients, 13 exhibited at least one escalation and were each matched to three non-escalated patients. A total of 28 escalation events were matched to 84 non-escalation episodes. The 30-min mean respiratory rate in escalated patients was 23 breaths per minute (bpm) ranging from 13 to 40 bpm, similar to the 22 bpm in non-escalated patients, although with less variability (range 14 to 31 bpm). However, higher respiratory rate variability, especially skewness over 1 day, was associated with higher incidence of escalation events. Our overall model, based on continuous data, had a moderate accuracy with an AUC 0.81 (95%CI: 0.73, 0.88) and a good specificity 0.93 (95%CI: 0.87, 0.99). Conclusion: Our pilot observational study suggests that respiratory rate variability as detected with continuous monitoring is associated with subsequent care escalation during the following 24 h. Continuous respiratory monitoring thus appears to be a valuable increment over intermittent monitoring. Strengths and limitations: Our study was the initial evaluation of Circadia contactless respiratory monitoring in COVID-19 patients who are at special risk of pulmonary deterioration. The major limitation is that the analysis was largely post hoc and thus needs to be confirmed in an out-of-sample population.

User Perceptions of Visual Blood: An International Mixed Methods Study on Novel Blood Gas Analysis Visualization.

Blood gas analysis plays a central role in modern medicine. Advances in technology have expanded the range of available parameters and increased the complexity of their interpretation. By applying user-centered design principles, it is possible to reduce the cognitive load associated with interpreting blood gas analysis. In this international, multicenter study, we explored anesthesiologists' perspectives on Visual Blood, a novel visualization technique for presenting blood gas analysis results. We conducted interviews with participants following two computer-based simulation studies, the first utilizing virtual reality (VR) (50 participants) and the second without VR (70 participants). Employing the template approach, we identified key themes in the interview responses and formulated six statements, which were rated using Likert scales from 1 (strongly disagree) to 5 (strongly agree) in an online questionnaire. The most frequently mentioned theme was the positive usability features of Visual Blood. The online survey revealed that participants found Visual Blood to be an intuitive method for interpreting blood gas analysis (median 4, interquartile range (IQR) 4-4, p < 0.001). Participants noted that minimal training was required to effectively learn how to interpret Visual Blood (median 4, IQR 4-4, p < 0.001). However, adjustments are necessary to reduce visual overload (median 4, IQR 2-4, p < 0.001). Overall, Visual Blood received a favorable response. The strengths and weaknesses derived from these data will help optimize future versions of Visual Blood to improve the presentation of blood gas analysis results.

The effect of intraoperative positive end expiratory pressure and tidal volume on postoperative acute kidney injury after orthopedic surgery.

BACKGROUND: To test whether higher intraoperative PEEP levels and/or higher TV levels are associated with higher incidence of postoperative AKI within the first postoperative week, in adult patients having orthopedic surgeries under general anesthesia. METHODS: We conducted a sub analysis of a non-randomized alternating intervention cross over study performed in patients undergoing orthopedic surgery under general anesthesia at Cleveland Clinic, Cleveland, OH. We included four different combinations of PEEP (5 or 8 cm H2 O) and TV (6 or 10 mL/kg of PBW) that alternated each week in the six orthopedic operating rooms. Our primary outcome was postoperative AKI defined by the KDIGO criteria with baseline creatinine as the closest preoperative value to the time of surgery obtained within 30 days and postoperative value as the highest creatinine value within 7 days after surgery. Secondary outcome was the maximum postoperative in-hospital creatinine level within seven postoperative days. MAIN RESULTS: A total of 1933 patients were included in the analysis. The incidence of AKI was 6.8% in the study population and similar in high TV versus low TV group and high PEEP versus low PEEP group. Neither TV nor PEEP significantly impacted AKI incidence. The estimated odds ratio of AKI comparing TV = 6 mL/kg to TV = 10 mL/kg was 0.96 (97.5% CI: 0.63, 1.46; p = .811); while the estimated odds ratio of AKI comparing PEEP = 5cm H2 O to PEEP = 8cm H2 O was 0.92 (97.5% CI: 0.60, 1.39; p = .623). No interaction was found between TV and PEEP on AKI. Additionally, neither TV nor PEEP had a significant effect on the seven postoperative day creatinine levels. CONCLUSION: Higher levels of PEEP or TV during mechanical ventilation in adult patients undergoing orthopedic surgeries under general anesthesia do not increase the odds of developing postoperative AKI within the narrow limits studied.

Avatar-based patient monitoring improves information transfer, diagnostic confidence and reduces perceived workload in intensive care units: computer-based, multicentre comparison study.

Patient monitoring is the foundation of intensive care medicine. High workload and information overload can impair situation awareness of staff, thus leading to loss of important information about patients' conditions. To facilitate mental processing of patient monitoring data, we developed the Visual-Patient-avatar Intensive Care Unit (ICU), a virtual patient model animated from vital signs and patient installation data. It incorporates user-centred design principles to foster situation awareness. This study investigated the avatar's effects on information transfer measured by performance, diagnostic confidence and perceived workload. This computer-based study compared Visual-Patient-avatar ICU and conventional monitor modality for the first time. We recruited 25 nurses and 25 physicians from five centres. The participants completed an equal number of scenarios in both modalities. Information transfer, as the primary outcome, was defined as correctly assessing vital signs and installations. Secondary outcomes included diagnostic confidence and perceived workload. For analysis, we used mixed models and matched odds ratios. Comparing 250 within-subject cases revealed that Visual-Patient-avatar ICU led to a higher rate of correctly assessed vital signs and installations [rate ratio (RR) 1.25; 95% CI 1.19-1.31; P < 0.001], strengthened diagnostic confidence [odds ratio (OR) 3.32; 95% CI 2.15-5.11, P < 0.001] and lowered perceived workload (coefficient - 7.62; 95% CI - 9.17 to - 6.07; P < 0.001) than conventional modality. Using Visual-Patient-avatar ICU, participants retrieved more information with higher diagnostic confidence and lower perceived workload compared to the current industry standard monitor.

Visual Blood, Visualisation of Blood Gas Analysis in Virtual Reality, Leads to More Correct Diagnoses: A Computer-Based, Multicentre, Simulation Study.

Interpreting blood gas analysis results can be challenging for the clinician, especially in stressful situations under time pressure. To foster fast and correct interpretation of blood gas results, we developed Visual Blood. This computer-based, multicentre, noninferiority study compared Visual Blood and conventional arterial blood gas (ABG) printouts. We presented six scenarios to anaesthesiologists, once with Visual Blood and once with the conventional ABG printout. The primary outcome was ABG parameter perception. The secondary outcomes included correct clinical diagnoses, perceived diagnostic confidence, and perceived workload. To analyse the results, we used mixed models and matched odds ratios. Analysing 300 within-subject cases, we showed noninferiority of Visual Blood compared to ABG printouts concerning the rate of correctly perceived ABG parameters (rate ratio, 0.96; 95% CI, 0.92-1.00; p = 0.06). Additionally, the study revealed two times higher odds of making the correct clinical diagnosis using Visual Blood (OR, 2.16; 95% CI, 1.42-3.29; p < 0.001) than using ABG printouts. There was no or, respectively, weak evidence for a difference in diagnostic confidence (OR, 0.84; 95% CI, 0.58-1.21; p = 0.34) and perceived workload (Coefficient, 2.44; 95% CI, -0.09-4.98; p = 0.06). This study showed that participants did not perceive the ABG parameters better, but using Visual Blood resulted in more correct clinical diagnoses than using conventional ABG printouts. This suggests that Visual Blood allows for a higher level of situation awareness beyond individual parameters' perception. However, the study also highlighted the limitations of today's virtual reality headsets and Visual Blood.

Association between obstructive sleep apnea and atrial fibrillation and delirium after cardiac surgery. Sub-analysis of DECADE trial.

BACKGROUND: Atrial fibrillation and delirium are common complications after cardiac surgery. Both are associated with increased Intensive Care Unit (ICU) and hospital length of stay, functional decline, 30-day mortality and increase in health care costs. Obstructive Sleep Apnea (OSA) induces deleterious effects in the cardiovascular and nervous systems. We hypothesized that adult patients with preoperative OSA have a higher incidence of postoperative atrial fibrillation and delirium than patients without OSA, after cardiac surgery. METHODS: Sub-analysis of the DECADE trial at Cleveland Clinic hospitals. Our exposure was OSA, defined by STOP-BANG questionnaire score higher than 5 and/or a preoperative diagnosis of OSA. The primary outcome was atrial fibrillation, defined by clinician diagnosis or documented arrhythmia. The secondary outcome was delirium assessed twice during the initial five postoperative days using the Confusion Assessment Method for ICU. We assessed the association between OSA, and atrial fibrillation and delirium using a logistic regression model adjusted for confounders using inverse probability of treatment weighting. RESULTS: 590 patients were included in the final analysis. 133 were diagnosed with OSA and 457 had no OSA. Satisfactory balance between groups for most confounders (absolute standardized difference < 0.10) was achieved after weighting. The atrial fibrillation incidence was 37% (n = 49) in the patients with OSA and 33% (n = 150) in the non-OSA patients. OSA was not associated with atrial fibrillation with an estimated odds ratio of 1.22 (95% CI: 0.75,1.99;p = 0.416). The delirium incidence was 17% (n = 22) in patients with OSA and 15% (n = 67) in the non-OSA patients. OSA was not associated with delirium with an estimated odds ratio of 0.93 (95% CI: 0.51,1.69;p = 0.800). CONCLUSION: In adult patients having cardiac surgery, OSA is not associated with a higher incidence of postoperative atrial fibrillation and delirium. These results suggest different prominent factors rather than OSA affect the incidence of these postoperative outcomes.

Relative contributions of anaemia and hypotension to myocardial infarction and renal injury: Post hoc analysis of the POISE-2 trial.

BACKGROUND: Hypotension and postoperative anaemia are associated with myocardial and renal injury after noncardiac surgery, but the interaction between them remains unknown. OBJECTIVES: To test the hypothesis that a double-hit of postoperative anaemia and hypotension synergistically worsens a 30-day composite of myocardial infarction (MI) and mortality and acute kidney injury (AKI). Characterising the interaction when hypotension and anaemia occur at same time on myocardial infarction and acute kidney injury. DESIGN: Post hoc analysis of the POISE-2 trial. SETTING: Patients were enrolled between July 2010 and December 2013 at 135 hospitals in 23 countries. PATIENTS: Adults at least 45 years old with known or suspected cardiovascular disease. We excluded patients without available postoperative haemoglobin measurements or hypotension duration records. Exposures were the lowest haemoglobin concentration and the average daily duration of SBP less than 90 mmHg within the first four postoperative days. MAIN OUTCOME MEASURES: The primary outcome was a collapsed composite of nonfatal MI and all-cause mortality during the initial 30 postoperative days; our secondary outcome was AKI. RESULTS: We included 7940 patients. The mean ±â€ŠSD lowest postoperative haemoglobin was 10 ±â€Š2 g dl -1 , and 24% of the patients had SBP less than 90 mmHg with daily duration ranging from 0 to 15 h. Four hundred and nine (5.2%) patients had an infarction or died within 30 postoperative days, and 417 (6.4%) patients developed AKI. Lowest haemoglobin concentrations less than 11 g dl -1 , and duration of SBP less than 90 mmHg was associated with greater hazard of composite outcome of nonfatal MI and all-cause mortality, as well as with AKI. However, we did not find significant multiplicative interactions between haemoglobin splines and hypotension duration on the primary composite or on AKI. CONCLUSION: Postoperative anaemia and hypotension were meaningfully associated with both our primary composite and AKI. However, lack of significant interaction suggests that the effects of hypotension and anaemia are additive rather than multiplicative. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01082874.

Effect of seasons on delirium in postoperative critically ill patients: a retrospective analysis

Abstract Background and objectives Postoperative delirium is common in critically ill patients and is known to have several predisposing and precipitating factors. Seasonality affects cognitive function which has a more dysfunctional pattern during winter. We, therefore, aimed to test whether seasonal variation is associated with the occurrence of delirium and hospital Length Of Stay (LOS) in critically ill non-cardiac surgical populations. Methods We conducted a retrospective analysis of adult patients recovering from non-cardiac surgery at the Cleveland Clinic between March 2013 and March 2018 who stayed in Surgical Intensive Care Unit (SICU) for at least 48 hours and had daily Confusion Assessment Method Intensive Care Unit (CAM-ICU) assessments for delirium. The incidence of delirium and LOS were summarized by season and compared using chi-square test and non-parametric tests, respectively. A logistic regression model was used to assess the association between delirium and LOS with seasons, adjusted for potential confounding variables. Results Among 2300 patients admitted to SICU after non-cardiac surgeries, 1267 (55%) had postoperative delirium. The incidence of delirium was 55% in spring, 54% in summer, 55% in fall and 57% in winter, which was not significantly different over the four seasons (p= 0.69). The median LOS was 12 days (IQR = [8, 19]) overall. There was a significant difference in LOS across the four seasons (p= 0.018). LOS during summer was 12% longer (95% CI: 1.04, 1.21; p= 0.002) than in winter. Conclusions In adult non-cardiac critically ill surgical patients, the incidence of postoperative delirium is not associated with season. Noticeably, LOS was longer in summer than in winter.

Effect of seasons on delirium in postoperative critically ill patients: a retrospective analysis.

BACKGROUND AND OBJECTIVES: Postoperative delirium is common in critically ill patients and is known to have several predisposing and precipitating factors. Seasonality affects cognitive function which has a more dysfunctional pattern during winter. We, therefore, aimed to test whether seasonal variation is associated with the occurrence of delirium and hospital Length Of Stay (LOS) in critically ill non-cardiac surgical populations. METHODS: We conducted a retrospective analysis of adult patients recovering from non-cardiac surgery at the Cleveland Clinic between March 2013 and March 2018 who stayed in Surgical Intensive Care Unit (SICU) for at least 48 hours and had daily Confusion Assessment Method Intensive Care Unit (CAM-ICU) assessments for delirium. The incidence of delirium and LOS were summarized by season and compared using chi-square test and non-parametric tests, respectively. A logistic regression model was used to assess the association between delirium and LOS with seasons, adjusted for potential confounding variables. RESULTS: Among 2300 patients admitted to SICU after non-cardiac surgeries, 1267 (55%) had postoperative delirium. The incidence of delirium was 55% in spring, 54% in summer, 55% in fall and 57% in winter, which was not significantly different over the four seasons (p = 0.69). The median LOS was 12 days (IQR = [8, 19]) overall. There was a significant difference in LOS across the four seasons (p = 0.018). LOS during summer was 12% longer (95% CI: 1.04, 1.21; p = 0.002) than in winter. CONCLUSIONS: In adult non-cardiac critically ill surgical patients, the incidence of postoperative delirium is not associated with season. Noticeably, LOS was longer in summer than in winter.

Preoperative triage to detect SARS-CoV-2 infection in surgical patients: lessons learned for resuming surgery.

PURPOSE: To define the impact of the COVID-19 outbreak on hospital surgical activity and assess the incidence of perioperative COVID-19 within two protocolized screening pathways for elective and non-elective surgery. METHODS: We conducted a prospective cohort study of adults undergoing surgery during the COVID-19 outbreak. The elective pathway included telephone surveys and a quantitative polymerase-chain-reaction test (RT-PCR) only for patients who were asymptomatic and at low risk of infection. Only patients with negative screening underwent surgery. In the non-elective pathway, preoperative screening was performed during the hospital admission. RESULTS: Among 835 patients considered for the elective pathway, 725 had negative RT-PCR results and underwent surgery. This reflects an 83% reduction in surgical activity from 2019. Moreover, 596 patients underwent non-elective surgery, representing a 28% reduction. Preoperatively, 39 patients (6.5%) tested positive for SARS-CoV-2 and underwent surgery through the non-elective pathway, vs. none in the elective pathway (p < 0.001). Postoperatively, 1.4% of elective surgery patients and 2.2% of non-elective surgery patients tested positive (p > 0.05). Mortality was higher in non-elective surgery (0.6% vs. 2.9%, p < 0.001) and in patients with COVID-19 (0% vs. 14%, p < 0.001). CONCLUSIONS: The low incidence of COVID-19 in elective surgeries during the outbreak demonstrates the importance and effectiveness of preoperative screening, combining surveys and RT-PCR.

Hypoventilation in the PACU is associated with hypoventilation in the surgical ward: Post-hoc analysis of a randomized clinical trial.

OBJECTIVE: To evaluate the association between early postoperative hypoventilation in the last hour of the post-anesthesia care unit (PACU) stay and hypoventilation during the rest of the first 48 postoperative hours in the surgical ward. DESIGN: Sub-analysis of a clinical trial. SETTING: PACU and surgical wards of a single medical center. PATIENTS: Adults having abdominal surgery under general anesthesia. INTERVENTIONS: Monitoring with a respiratory volume monitor from admission to PACU until the earlier of 48 h after surgery or discharge. MEASUREMENTS: The exposure was having at least one low minute-ventilation (MV) event during the last hour of PACU stay, defined as MV lower than 40% the predicted value lasting at least 1 min. The primary outcome was low MV events lasting at least 2 min during the rest of the first 48 postoperative hours, while in the surgical ward. The secondary outcome was the rate of low MV events per monitored hour. MAIN RESULTS: Data of 292 patients were analyzed, of which 20 (6.8%) patients had a low MV event in PACU. Low MV events in the surgical ward were found in 81 (28%) patients. All patients who had low MV events in PACU had events again in the ward, while 61/272 (22%) had an event in the ward but not in PACU. The incidence rate of low MV events per hour was 24 (95% CI: 13, 46) among patients having an event in the PACU, and 2 (1, 4) among those who did not. CONCLUSIONS: In adults recovering from abdominal surgery, events of hypoventilation during the first postoperative hour are associated with similar events during the rest of the first 48 postoperative hours, with positive predictive value approaching 100%. Sixty-one patients had ward hypoventilation that was not preceded by hypoventilation in PACU.

New-Onset Atrial Fibrillation in Patients Undergoing Liver Transplantation: Retrospective Analysis of Risk Factors and Outcomes.

OBJECTIVE: The authors aimed to identify predictors of new-onset postoperative atrial fibrillation (POAF) during the initial 90 days following liver transplantation, and to assess the association between POAF in-hospital and 1-year mortality. DESIGN: A retrospective cohort study. SETTING: At a university hospital between 2005 and 2017. PATIENTS: Adults without a history of preoperative atrial fibrillation who underwent orthotopicliver transplantation. MEASUREMENT AND MAIN RESULTS: The authors assessed the univariate association between new-onset of POAF in the postoperative period and each potential factor through a logistic regression model. Moreover, they explored predictors for POAF through stepwise selection. Finally, the authors assessed the relationship between POAF and in-hospital and 1-year mortality using logistic regression models, and whether the duration of atrial fibrillation was associated with in-hospital and 1-year mortality. Among 857 patients, 89 (10.4%) developed POAF. Using only preoperative variables, pulmonary hypertension, age, Model for End-Stage Liver Disease (MELD) score, and White race were identified as the most important predictors. Model discrimination was 0.75 (95% CI: 0.69-0.80), and incorporating intraoperative variables was 0.77 (95% CI: 0.72-0.82). In-hospital mortality was observed in 7.2% (6/83) of patients with new-onset of POAF, and in 2.8% (22/768) without, with confounder-adjusted odds ratio (OR) 1.00 (97.5% CI: 0.29,3.45; p = 0.996). One-year mortality was 22.4% (20/89) in patients who developed POAF and 8.3% (64/768) in patients who did not, confounder-adjusted OR 2.64 (97.5% CI: 1.35-5.16; p = 0.001). The duration of POAF did not affect long-term postoperative mortality. CONCLUSION: Preoperative, mostly unmodifiable comorbidities are important risk factors for new-onset POAF after liver transplantation. The POAF was not associated with in-hospital mortality, but with increased 1-year mortality. Once developed, the duration of POAF did not affect long-term mortality after a liver transplant.

Tidal Volume and Positive End-expiratory Pressure and Postoperative Hypoxemia during General Anesthesia: A Single-center Multiple Crossover Factorial Cluster Trial.

BACKGROUND: Intraoperative mechanical ventilation is a major component of general anesthesia. The extent to which various intraoperative tidal volumes and positive end-expiratory pressures (PEEP) effect on postoperative hypoxia and lung injury remains unclear. We hypothesized that adults having orthopedic surgery, ventilation using different tidal volumes and PEEP levels affect the oxygenation within first hour in the postoperative care unit. METHODS: We conducted a two-by-two factorial crossover cluster trial at the Cleveland Clinic Main Campus. We enrolled patients having orthopedic surgery with general anesthesia who were assigned to factorial clusters with tidal volumes of 6 or 10 ml/kg of predicted body weight and to PEEP of 5 or 8 cm H2O in 1-week clusters. The primary outcome was the effect of tidal volume or PEEP on time-weighted average peripheral oxygen saturation measured by pulse oximetry divided by the fraction of inspired oxygen (Spo2/Fio2 ratio) during the initial postoperative hour. RESULTS: We enrolled 2,860 patients who had general anesthesia for orthopedic surgery from September 2018 through October 2020. The interaction between tidal volume and PEEP was not significant (P = 0.565). The mean ± SD time-weighted average of Spo2/Fio2 ratio was 353 ± 47 and not different in patients assigned to high and low tidal volume (estimated effect, 3.5%; 97.5% CI, -0.4% to 7.3%; P = 0.042), for those assigned to high and low PEEP (estimated effect, -0.2%; 97.5% CI, -4.0% to 3.6%; P = 0.906). We did not find significant difference in ward Spo2/Fio2 ratio, pulmonary complications, and duration of hospitalization among patients assigned to various tidal volumes and PEEP levels. CONCLUSIONS: Among adults having major orthopedic surgery, postoperative oxygenation is similar, with tidal volumes between 6 and 10 ml/kg and PEEP between 5 and 8 cm H2O. Our results suggest that any combination of tidal volumes between 6 and 10 ml/kg and PEEP between 5 versus 8 ml cm H2O can be used safely for orthopedic surgery.