Association of Mechanical Energy and Power with Postoperative Pulmonary Complications in Lung Resection Surgery: A Post Hoc Analysis of Randomized Clinical Trial Data.

BACKGROUND: Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context, and neither parameter has been studied in the context of thoracic surgery utilizing one-lung ventilation. METHODS: The relationships between ME variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n = 1,170). Time-weighted average MP and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of time-weighted average MP and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome. RESULTS: In 1,055 patients analyzed, pulmonary complications occurred in 41% (431 of 1,055). The median (interquartile ranges) ME and time-weighted average MP in patients who developed postoperative pulmonary complications versus those who did not were 1,146 (811 to 1,530) J versus 924 (730 to 1,240) J (P < 0.001), and 6.9 (5.5 to 8.7) J/min versus 6.7 (5.2 to 8.5) J/min (P = 0.091), respectively. ME was independently associated with postoperative pulmonary complications (ORadjusted, 1.44 [95% CI, 1.16 to 1.80]; P = 0.001). However, the association between time-weighted average MP and postoperative pulmonary complications was time-dependent, and time-weighted average MP was significantly associated with postoperative pulmonary complications in cases utilizing longer periods of mechanical ventilation (210 min or greater; ORadjusted, 1.46 [95% CI, 1.11 to 1.93]; P = 0.007). Normalization of ME and time-weighted average MP either to predicted body weight or to respiratory system compliance did not alter these associations. CONCLUSIONS: ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with postoperative pulmonary complications in thoracic surgery.

Effect of Sevoflurane Anesthesia on Diastolic Function: A Prospective Observational Study.

BACKGROUND: The effect of sevoflurane on left ventricular diastolic function is not well understood. We hypothesized that parameters of diastolic function may improve under sevoflurane anesthesia in patients with preexisting diastolic dysfunction compared to patients with normal diastolic function. METHODS: This observational study included 60 patients undergoing breast surgery or laparoscopic cholecystectomy. Patients were assigned to diastolic dysfunction (n = 34) or normal (n = 26) groups of septal e' < 8 or ≥ 8.0 cm/s on the first thoracic echocardiography (TTE) performed before anesthesia. During anesthesia, sevoflurane was maintained at 1 to 2 minimum alveolar concentration (MAC) to maintain the bispectral index at 40 to 50. At the end of surgery, the second TTE was performed under 0.8 to 1 MAC of sevoflurane with the patient breathing spontaneously without ventilator support. Primary end point was the percentage change (Δ) of e' on 2 TTEs (Δe'). Secondary end points were ΔE/e', Δleft atrial volume index (ΔLAVI), and Δtricuspid regurgitation maximum velocity (ΔTR Vmax). These percentage changes (Δ) were compared between diastolic dysfunction and normal groups. RESULTS: e' (Δe': 30 [6, 64] vs 0 [-18, 11]%; P < .001), mitral inflow E wave velocity (E), mitral inflow E/A ratio (E/A), and mitral E velocity deceleration time (DT) improved significantly in diastolic dysfunction group compared to normal group. LAVI decreased in diastolic dysfunction group but did not reach statistical significance between the 2 groups (ΔLAVI:-15 [-31, -3] vs -4 [-20, 10]%, P = .091). ΔE/e' was not different between the 2 groups (11 [-16, 26] vs 12 [-9, 22]%, P = .853) (all: median [interquartile range, IQR]). TR was minimal in both groups. CONCLUSIONS: In this study, echocardiographic parameters of diastolic function, including septal e', E, E/A, and DT, improved with sevoflurane anesthesia in patients with preexisting diastolic dysfunction, but remained unchanged in patients with normal diastolic function.

Comparison of tracheal versus esophageal temperatures during laparoscopic surgery.

PURPOSE: Recently, endotracheal tubes with an embedded temperature sensor in the inner surface of the tube cuff (temperature tracheal tubes) have been developed. We sought to assess whether temperature tracheal tubes show a good agreement with esophageal temperature probes during surgery. METHODS: We enrolled 40 patients who underwent laparoscopic surgery in an observational study. The tracheas of all patients were intubated with a temperature tracheal tube, and an esophageal temperature probe was inserted into the esophagus. Tracheal and esophageal temperatures were recorded at 15-min intervals until the end of surgery. Temperatures from both devices were analyzed using Bland-Altman analysis, four-quadrant plots, and polar plots. RESULTS: We analyzed 261 data points from 36 patients. Temperatures ranges were 34.2 °C to 36.6 °C for the tracheal temperature tube and 34.7 °C to 37.2 °C for the esophageal temperature probe. Bland-Altman analysis showed an acceptable agreement between the two devices, with an overall mean bias (95% limit of agreement) of -0.3 °C (-0.8 °C to 0.1 °C) and a percentage error of 3%; the trending ability (temperature changes over time) between the two devices showed a concordance rate of 94% in four-quadrant plot (cut-off ≥ 92%), but this was higher than the acceptable mean angular bias of 177° (cut-off < ± 5°) and radial limits of agreement of 52° (cut-off < ± 30°) in the polar plot. Bronchoscopy during extubation and patient interviews at six hours postoperatively revealed no serious injuries related to the use of the temperature tracheal tube. CONCLUSION: The temperature tracheal tube showed an acceptable overall mean bias of -0.3 °C and a percentage error of 3%, but incompatible trending ability with the esophageal temperature probe. STUDY REGISTRATION: cris.nih.go.kr (KCT0007265); 22 April 2022.

RéSUMé: OBJECTIF: Récemment, des sondes endotrachéales munies d'un capteur de température intégré dans la surface interne du ballonnet de la sonde (sondes thermiques trachéales) ont été mises au point. Nous avons cherché à évaluer si les sondes trachéales de température montraient une bonne concordance avec les sondes thermiques œsophagiennes pendant la chirurgie. MéTHODE: Nous avons recruté 40 patient·es ayant bénéficié d'une chirurgie par laparoscopie dans le cadre d'une étude observationnelle. Les trachées de tou·tes les patient·es ont été intubées à l'aide d'une sonde trachéale de température et une sonde thermique œsophagienne a été insérée dans l'œsophage. Les températures trachéale et œsophagienne ont été enregistrées à des intervalles de 15 minutes jusqu'à la fin de la chirurgie. Les températures des deux appareils ont été analysées à l'aide d'une analyse de Bland-Altman, de diagrammes à quatre quadrants et de diagrammes polaires. RéSULTATS: Nous avons analysé 261 points de données provenant de 36 patient·es. Les plages de température allaient de 34,2 °C à 36,6 °C pour la sonde trachéale de température et de 34,7 °C à 37,2 °C pour la sonde thermique œsophagienne. L'analyse de Bland-Altman a montré une concordance acceptable entre les deux dispositifs, avec un biais moyen global (limite de 95 % de la concordance) de −0,3 °C (−0,8 °C à 0,1 °C) et un pourcentage d'erreur de 3 %; la capacité de tendance (changements de température au fil du temps) entre les deux dispositifs a montré un taux de concordance de 94 % dans un diagramme à quatre quadrants (limite ≥ 92 %), mais cette capacité était plus élevée que le biais angulaire moyen acceptable de 177° (limite < ± 5°) et que les limites radiales de l'accord de 52° (limite < ± 30°) dans le diagramme polaire. La bronchoscopie réalisée lors de l'extubation et les entretiens avec les patient·es six heures après l'opération n'ont révélé aucune blessure grave liée à l'utilisation de la sonde trachéale de température. CONCLUSION: La sonde trachéale de température a montré un biais moyen global acceptable de −0,3 °C et un pourcentage d'erreur de 3 %, mais une capacité de tendance incompatible avec la sonde thermique œsophagienne. ENREGISTREMENT DE L'éTUDE: cris.nih.go.kr (KCT0007265); 22 avril 2022.

Comparison of high-flow nasal cannula and conventional nasal cannula during deep sedation for endoscopic submucosal dissection: a randomized controlled trial.

PURPOSE: Adequate oxygenation and airway management during deep sedation can be challenging. We investigated the effect of high-flow nasal cannula (group HF) and conventional nasal cannula (group CO) during sedation for endoscopic submucosal dissection (ESD). METHODS: Patients undergoing ESD with deep sedation were enrolled. The primary outcome was difference in lowest oxygen saturation (SpO2) between the groups. Incidence of hypoxia (SpO2 < 90%), patients with SpO2 < 95%, hypercapnia, and airway interventions; operator satisfaction; and adverse events were recorded. RESULTS: Thirty-two patients in each group completed the study. The mean of minimum SpO2 values was significantly higher in group HF than in group CO (96.8% ± 4.2% vs. 93.3% ± 5.3%, p = 0.005). The incidence of hypoxia was comparable between the groups (4 [12.5%] vs. 6 [18.8%], p = 0.491); however, patients with SpO2 < 95% were significantly less in group HF (5 [15.6%] vs. 18 [56.3%], p = 0.003). Incidence of hypercapnia was higher in group HF than in group CO (14 [46.7%] vs. 5 [16.7%], p = 0.013). Airway rescue interventions were significantly less common in group HF. Satisfaction of operators and post-procedural complications were comparable between the two groups. In multivariable analysis, group CO and higher body mass index were risk factors for airway managements (odds ratio [95% confidence interval]: 6.204 [1.784-21.575], p = 0.004; 1.337 [1.043-1.715], p = 0.022, respectively). CONCLUSIONS: Compared to conventional nasal cannula, high-flow nasal cannula maintained higher minimum SpO2 value during deep sedation with propofol-remifentanil for ESD. TRIAL REGISTRATION: Clinical Trial Registry of the Republic of Korea (KCT0006618, https://cris.nih.go.kr ; registered September 29, 2021; principal investigator: Ji Won Choi).

Driving pressure-guided ventilation and postoperative pulmonary complications in thoracic surgery: a multicentre randomised clinical trial.

BACKGROUND: Airway driving pressure, easily measured as plateau pressure minus PEEP, is a surrogate for alveolar stress and strain. However, the effect of its targeted reduction remains unclear. METHODS: In this multicentre trial, patients undergoing lung resection surgery were randomised to either a driving pressure group (n=650) receiving an alveolar recruitment/individualised PEEP to deliver the lowest driving pressure or to a conventional protective ventilation group (n=650) with fixed PEEP of 5 cm H2O. The primary outcome was a composite of pulmonary complications within 7 days postoperatively. RESULTS: The modified intention-to-treat analysis included 1170 patients (mean [standard deviation, sd]; age, 63 [10] yr; 47% female). The mean driving pressure was 7.1 cm H2O in the driving pressure group vs 9.2 cm H2O in the protective ventilation group (mean difference [95% confidence interval, CI]; -2.1 [-2.4 to -1.9] cm H2O; P<0.001). The incidence of pulmonary complications was not different between the two groups: driving pressure group (233/576, 40.5%) vs protective ventilation group (254/594, 42.8%) (risk difference -2.3%; 95% CI, -8.0% to 3.3%; P=0.42). Intraoperatively, lung compliance (mean [sd], 42.7 [12.4] vs 33.5 [11.1] ml cm H2O-1; P<0.001) and Pao2 (median [inter-quartile range], 21.5 [14.5 to 30.4] vs 19.5 [13.5 to 29.1] kPa; P=0.03) were higher and the need for rescue ventilation was less frequent (6.8% vs 10.8%; P=0.02) in the driving pressure group. CONCLUSIONS: In lung resection surgery, a driving pressure-guided ventilation improved pulmonary mechanics intraoperatively, but did not reduce the incidence of postoperative pulmonary complications compared with a conventional protective ventilation. CLINICAL TRIAL REGISTRATION: NCT04260451.

Enhanced Recovery After Surgery Program and Opioid Consumption in Pulmonary Resection Surgery: A Retrospective Observational Study.

BACKGROUND: Pulmonary resection surgery causes severe postoperative pain and usually requires opioid-based analgesia, particularly in the early postoperative period. However, the administration of large amounts of opioids is associated with various adverse events. We hypothesized that patients who underwent pulmonary resection under an enhanced recovery after surgery (ERAS) program consumed fewer opioids than patients who received conventional treatment. METHODS: A total of 2147 patients underwent pulmonary resection surgery between August 2019 and December 2020. Two surgeons (25%) at our institution implemented the ERAS program for their patients. After screening, the patients were divided into the ERAS and conventional groups based on the treatment they received. The 2 groups were then compared after the stabilized inverse probability of treatment weighting. The primary end point was the total amount of opioid consumption from surgery to discharge. The secondary end points included daily average and highest pain intensity scores during exertion, opioid-related adverse events, and clinical outcomes, such as length of intensive care unit (ICU) stay, hospital stay, and postoperative complication grade defined by the Clavien-Dindo classification. Additionally, the number of patients discharged without opioids prescription was assessed. RESULTS: Finally, 2120 patients were included in the analysis. The total amount of opioid consumption (median [interquartile range]) after surgery until discharge was lower in the ERAS group (n = 260) than that in the conventional group (n = 1860; morphine milligram equivalents, 44 [16-122] mg vs 208 [146-294] mg; median difference, -143 mg; 95% CI, -154 to -132; P < .001). The number of patients discharged without opioids prescription was higher in the ERAS group (156/260 [60%] vs 329/1860 [18%]; odds ratio, 7.0; 95% CI, 5.3-9.3; P < .001). On operation day, both average pain intensity score during exertion (3.0 ± 1.7 vs 3.5 ± 1.8; mean difference, -0.5; 95% CI, -0.8 to -0.3; P < .001) and the highest pain intensity score during exertion (5.5 ± 2.1 vs 6.4 ± 1.7; mean difference, -0.8; 95% CI, -1.0 to -0.5; P < .001) were lower in the ERAS group than in the conventional group. There were no significant differences in the length of ICU stay, hospital stay, or Clavien-Dindo classification grade. CONCLUSIONS: Patients who underwent pulmonary resection under the ERAS program consumed fewer opioids than those who received conventional management while maintaining no significant differences in clinical outcomes.

Continuous Titration of Inspired Oxygen Using Oxygen Reserve Index to Decrease Oxygen Exposure During One-Lung Ventilation: A Randomized Controlled Trial.

BACKGROUND: A high fraction of inspired oxygen (Fio2) is administered during one-lung ventilation (OLV). However, a high Fio2 is not physiologic and may lead to various complications. We hypothesized that continuous titration of Fio2 using the oxygen reserve index (ORI) reduces oxygen exposure compared to conventional management during OLV. METHODS: In this randomized, double-blinded trial, patients undergoing thoracic surgery were assigned to an ORI (n = 64) or a control group (n = 60). In the ORI group, ORI was continuously displayed using multiwavelength pulse co-oximetry (Masimo) between 0 and 1 (0, no reserve; 1, maximum reserve), and Fio2 was titrated for a target ORI of 0.21 at 5-minute intervals during OLV. In the control group, Fio2 was adjusted using arterial blood gas analysis measured at 15 minutes after OLV initiation. The primary end point was the time-weighted average Fio2 during OLV. RESULTS: Overall, time-weighted average Fio2 did not differ between the groups (control versus ORI: median [interquartile range], 0.87 [0.73-1.00] vs 0.82 [0.68-0.93]; P = .09). However, in a subgroup analysis, the ORI group reduced time-weighted average Fio2 after pulmonary vascular ligation compared to the control group (control versus ORI: median [interquartile range], 0.75 [0.70-1.00] vs 0.72 [0.59-0.89]; P = .0261). The incidence of intraoperative hypoxia (arterial oxygen saturation [Spo2] <94%; control versus ORI: 32% [19/60; 95% confidence interval (CI), 20-45] vs 19% [12/64; 95% CI, 10-31]; P = .09), and postoperative complications within the first 7 days did not differ between the groups. CONCLUSIONS: ORI-guided continuous Fio2 titration does not reduce overall oxygen exposure during OLV.

Safety of Rigid Bronchoscopy for Therapeutic Intervention at the Intensive Care Unit Bedside.

Background and Objective: Although rigid bronchoscopy is generally performed in the operating room (OR), the intervention is sometimes emergently required at the intensive care unit (ICU) bedside. The aim of this study is to evaluate the safety of rigid bronchoscopy at the ICU bedside. Materials and Methods: We retrospectively analyzed medical records of patients who underwent rigid bronchoscopy while in the ICU from January 2014 to December 2020. According to the location of rigid bronchoscopic intervention, patients were classified into the ICU group (n = 171, cases emergently performed at the ICU bedside without anesthesiologists) and the OR group (n = 165, cases electively performed in the OR with anesthesiologists). The risk of intra- and post-procedural complications in the ICU group was analyzed using multivariable logistic regression, with the OR group as the reference category. Results: Of 336 patients, 175 (52.1%) were moribund and survival was not expected without intervention, and 170 (50.6%) received invasive respiratory support before the intervention. The most common reasons for intervention were post-intubation tracheal stenosis (39.3%) and malignant airway obstruction (34.5%). Although the overall rate of intra-procedural complications did not differ between the two groups (86.0% vs. 80.6%, p = 0.188), post-procedural complications were more frequent in the ICU group than in the OR group (24.0% vs. 12.1%, p = 0.005). Severe complications requiring unexpected invasive management occurred only post-procedurally and were more common in the ICU group (10.5% vs. 4.8%, p = 0.052). In the fully adjusted model, the ICU group had increased odds for severe post-procedural complications, but statistical significance was not observed (odds ratio, 2.54; 95% confidence interval, 0.73-8.88; p = 0.144). Conclusions: Although general anesthesia is generally considered the gold standard for rigid bronchoscopy, our findings indicate that rigid bronchoscopy may be safely performed at the ICU bedside in selective cases of emergency. Moreover, adequate patient selection and close post-procedural monitoring are required to prevent severe complications.

Pressure Support versus Spontaneous Ventilation during Anesthetic Emergence-Effect on Postoperative Atelectasis: A Randomized Controlled Trial.

BACKGROUND: Despite previous reports suggesting that pressure support ventilation facilitates weaning from mechanical ventilation in the intensive care unit, few studies have assessed its effects on recovery from anesthesia. The authors hypothesized that pressure support ventilation during emergence from anesthesia reduces postoperative atelectasis in patients undergoing laparoscopic surgery using the Trendelenburg position. METHODS: In this randomized controlled double-blinded trial, adult patients undergoing laparoscopic colectomy or robot-assisted prostatectomy were assigned to either the pressure support (n = 50) or the control group (n = 50). During emergence (from the end of surgery to extubation), pressure support ventilation was used in the pressure support group versus intermittent manual assistance in the control group. The primary outcome was the incidence of atelectasis diagnosed by lung ultrasonography at the postanesthesia care unit (PACU). The secondary outcomes were Pao2 at PACU and oxygen saturation measured by pulse oximetry less than 92% during 48 h postoperatively. RESULTS: Ninety-seven patients were included in the analysis. The duration of emergence was 9 min and 8 min in the pressure support and control groups, respectively. The incidence of atelectasis at PACU was lower in the pressure support group compared to that in the control group (pressure support vs. control, 16 of 48 [33%] vs. 28 of 49 [57%]; risk ratio, 0.58; 95% CI, 0.35 to 0.91; P = 0.024). In the PACU, Pao2 in the pressure support group was higher than that in the control group (92 ± 26 mmHg vs. 83 ± 13 mmHg; P = 0.034). The incidence of oxygen saturation measured by pulse oximetry less than 92% during 48 h postoperatively was not different between the groups (9 of 48 [19%] vs. 11 of 49 [22%]; P = 0.653). There were no adverse events related to the study protocol. CONCLUSIONS: The incidence of postoperative atelectasis was lower in patients undergoing either laparoscopic colectomy or robot-assisted prostatectomy who received pressure support ventilation during emergence from general anesthesia compared to those receiving intermittent manual assistance.

Prediction of Pleural Adhesions by Lung Ultrasonography: An Observational Study.

OBJECTIVE: Pleural adhesion makes video-assisted thoracoscopic surgery (VATS) an arduous procedure and can increase postoperative pain from accompanying adhesiolysis. For the present study, the feasibility of lung ultrasonography for the prediction of pleural adhesions and postoperative pain in VATS was investigated. DESIGN: Blinded, prospective, observational study. SETTING: Tertiary teaching hospital, Seoul, South Korea. PARTICIPANTS: Sixty patients (American Society of Anesthesiologists physical status I to III) scheduled to undergo VATS were assessed for eligibility. After exclusions, 53 patients were enrolled and followed-up. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were evaluated with lung ultrasonography during deep spontaneous respiration before induction of anesthesia, and surgeons confirmed the presence of pleural adhesions during the surgery. Pain was evaluated using a numeric rating scale and by the amount of opioid consumption until 24 hours postoperatively. Lung ultrasonography showed acceptable predictability of pleural adhesions, with the area under the receiver operating characteristic curve (0.75, 95% confidence interval [CI] 0.67-0.83) and high specificity (0.97, 95% CI 0.91-0.99) but low sensitivity (0.53, 95% CI 0.38-0.68). The pain score was not different between sonographic adhesion (+) and (-) groups; however, the sonographic adhesion (+) group consumed more opioids until 24 hours postoperatively (fentanyl 675 [558-805] µg v 420 [356-476] µg; p < 0.001). CONCLUSIONS: Lung ultrasonography may help with planning postoperative pain management in VATS; however, it was a better tool for ruling out rather than detecting pleural adhesions.

Phage Display Screening of Bovine Antibodies to Foot-and-Mouth Disease Virus and Their Application in a Competitive ELISA for Serodiagnosis.

For serodiagnosis of foot-and-mouth disease virus (FMDV), monoclonal antibody (MAb)-based competitive ELISA (cELISA) is commonly used since it allows simple and reproducible detection of antibody response to FMDV. However, the use of mouse-origin MAb as a detection reagent is questionable, as antibody responses to FMDV in mice may differ in epitope structure and preference from those in natural hosts such as cattle and pigs. To take advantage of natural host-derived antibodies, a phage-displayed scFv library was constructed from FMDV-immune cattle and subjected to two separate pannings against inactivated FMDV type O and A. Subsequent ELISA screening revealed high-affinity scFv antibodies specific to a serotype (O or A) as well as those with pan-serotype specificity. When BvO17, an scFv antibody specific to FMDV type O, was tested as a detection reagent in cELISA, it successfully detected FMDV type O antibodies for both serum samples from vaccinated cattle and virus-challenged pigs with even higher sensitivity than a mouse MAb-based commercial FMDV type O antibody detection kit. These results demonstrate the feasibility of using natural host-derived antibodies such as bovine scFv instead of mouse MAb in cELISA for serological detection of antibody response to FMDV in the susceptible animals.

Association between intraoperative hypotension and postoperative myocardial injury in patients with prior coronary stents undergoing high-risk surgery: a retrospective study.

PURPOSE: We conducted a single-center retrospective study to evaluate the effects of intraoperative hypotension (IOH) on postoperative myocardial injury during major noncardiac surgery in patients with prior coronary stents with preoperatively normal cardiac troponin I levels. Although IOH is assumed to increase the risk of postoperative myocardial injury in patients with prior coronary stents, the level and duration of hazardous low blood pressure have not been clarified. METHODS: Of 2517 patients with prior coronary stents undergoing noncardiac surgery between January 2010 and March 2017, we analyzed 195 undergoing major surgery (vascular, abdominal, and thoracic surgery) who had a normal preoperative high-sensitivity cardiac troponin I (hs-cTnI) level and were followed up postoperatively within 3 days. Postoperative myocardial injury was defined as a hs-cTnI level greater than the 99th percentile reference value. Primary IOH exposure was defined as a decrease of ≥ 50%, 40%, or 30% from the preinduction mean blood pressure. Additional definition of IOH was absolute mean blood pressure < 70, < 60 or < 50 mmHg. Multivariate logistic regression was used to model the exposure and myocardial injury. RESULTS: Myocardial injury occurred in 53 (27.2%) cases. The predefined levels of IOH were not significantly associated with postoperative myocardial injury, but intraoperative continuous inotropes/vasopressors use was significantly higher in patients with myocardial injury (P = 0.004). Operation time ≥ 166 min (OR = 2.823, 95% CI 1.184-6.731, P = 0.019) and abdominal vascular surgery (OR = 2.693, 95% CI 1.213-5.976, P = 0.015) were independent risk factors for myocardial injury. CONCLUSION: Although patients with prior coronary stents with normal hs-cTnI levels did not show association between varying levels of IOH and postoperative myocardial injury after noncardiac surgery, intraoperative need of continuous inotropes/vasopressors was higher in patients with postoperative myocardial injury. Abdominal vascular surgery and surgical time were independent risk factors for myocardial injury after surgery.

Driving Pressure during Thoracic Surgery: A Randomized Clinical Trial.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: Driving pressure (plateau minus end-expiratory airway pressure) is a target in patients with acute respiratory distress syndrome, and is proposed as a target during general anesthesia for patients with normal lungs. It has not been reported for thoracic anesthesia where isolated, inflated lungs may be especially at risk. WHAT THIS ARTICLE TELLS US THAT IS NEW: In a double-blinded, randomized trial (292 patients), minimized driving pressure compared with standard protective ventilation was associated with less postoperative pneumonia or acute respiratory distress syndrome. BACKGROUND: Recently, several retrospective studies have suggested that pulmonary complication is related with driving pressure more than any other ventilatory parameter. Thus, the authors compared driving pressure-guided ventilation with conventional protective ventilation in thoracic surgery, where lung protection is of the utmost importance. The authors hypothesized that driving pressure-guided ventilation decreases postoperative pulmonary complications more than conventional protective ventilation. METHODS: In this double-blind, randomized, controlled study, 292 patients scheduled for elective thoracic surgery were included in the analysis. The protective ventilation group (n = 147) received conventional protective ventilation during one-lung ventilation: tidal volume 6 ml/kg of ideal body weight, positive end-expiratory pressure (PEEP) 5 cm H2O, and recruitment maneuver. The driving pressure group (n = 145) received the same tidal volume and recruitment, but with individualized PEEP which produces the lowest driving pressure (plateau pressure-PEEP) during one-lung ventilation. The primary outcome was postoperative pulmonary complications based on the Melbourne Group Scale (at least 4) until postoperative day 3. RESULTS: Melbourne Group Scale of at least 4 occurred in 8 of 145 patients (5.5%) in the driving pressure group, as compared with 18 of 147 (12.2%) in the protective ventilation group (P = 0.047, odds ratio 0.42; 95% CI, 0.18 to 0.99). The number of patients who developed pneumonia or acute respiratory distress syndrome was less in the driving pressure group than in the protective ventilation group (10/145 [6.9%] vs. 22/147 [15.0%], P = 0.028, odds ratio 0.42; 95% CI, 0.19 to 0.92). CONCLUSIONS: Application of driving pressure-guided ventilation during one-lung ventilation was associated with a lower incidence of postoperative pulmonary complications compared with conventional protective ventilation in thoracic surgery.

Intraoperative use of dexmedetomidine for the prevention of emergence agitation and postoperative delirium in thoracic surgery: a randomized-controlled trial.

PURPOSE: We investigated whether preventive use of dexmedetomidine during surgery was effective for reducing emergence agitation and postoperative delirium. METHODS: In this double-blind randomized-controlled trial, 143 patients undergoing thoracoscopic lung resection surgery were randomly assigned to the dexmedetomidine-sevoflurane (DEX-Sevo, n = 73) or sevoflurane (Sevo, n = 70) groups. Dexmedetomidine or saline administration was started after inducing anesthesia and continued until the end of surgery at a fixed dose (0.5 µg·kg-1·hr-1). The primary endpoint was the incidence of delirium up until the end of postoperative day 3. Emergence agitation and postoperative delirium were measured with the Riker sedation agitation scale and the confusion assessment method, respectively. The secondary endpoints were serum cytokine and catecholamine levels. RESULTS: The DEX-Sevo group showed less frequent emergence agitation than the Sevo group (13% vs 35%, respectively; relative risk, 0.38; 95% confidence interval [CI], 0.18 to 0.79; P = 0.011) but the incidence of delirium after discharge from the postanesthesia care unit was not different (25% vs 25%, DEX-Sevo vs Sevo). Both pro- and anti-inflammatory cytokines were lower in the DEX-Sevo group than in the Sevo group. Nevertheless, the interleukin (IL)6/IL10 ratio (median difference, 5.8; 95% CI,1.8 to 10.0; P = 0.012) and IL8/IL10 ratio (median difference, 0.8; 95% CI, 0.2 to 1.3; P = 0.007) were higher in the DEX-Sevo group than in the Sevo group, indicating a pro-inflammatory cytokine balance in the DEX-Sevo group. Norepinephrine and epinephrine levels were lower in the DEX-Sevo group than in the Sevo group (both, P < 0.001). CONCLUSIONS: Intraoperative dexmedetomidine reduced emergence agitation but not postoperative delirium in patients undergoing thoracic surgery. Dexmedetomidine seemed to affect emergence agitation through catecholamines, but not through an anti-inflammatory action. Trial registration Clinical Research Information Service (KCT 0001877); registered 7 April, 2016.

RéSUMé: OBJECTIF: Nous avons cherché à savoir si l'utilisation préventive de dexmédétomidine au cours de la chirurgie pouvait réduire la survenue de l'agitation au réveil et du delirium postopératoire. MéTHODES: Dans cette étude randomisée, contrôlée à double insu, 143 patients subissant une résection pulmonaire par thoracoscopie ont été randomisés dans un groupe recevant dexmédétomidine-sévoflurane (DEX-Sévo, n = 73) ou dans un groupe recevant seulement du sévoflurane (Sévo, n = 70). L'administration de dexmédétomidine ou de solution saline a débuté après l'induction de l'anesthésie et a continué jusqu'à la fin de l'intervention à une dose fixe de 0,5 µg·kg−1·h−1. Le critère d'évaluation principal était l'incidence du delirium jusqu'à la fin du 3e jour postopératoire. La survenue de l'agitation au réveil et du delirium postopératoire a été mesurée avec, respectivement, l'échelle d'agitation sous sédation de Riker et la méthode d'évaluation de la confusion. Les critères d'évaluation secondaires étaient les taux sériques de cytokines et de catécholamines. RéSULTATS: La survenue d'une agitation au réveil a été moins fréquente dans le groupe DEX-Sévo que dans le groupe Sévo (respectivement, 13 % contre 35 %; risque relatif, 0,38; intervalle de confiance [IC] à 95 % : 0,18 à 0,79; P = 0,011), mais l'incidence du delirium après congé de la salle de réveil n'a pas été différente entre les groupes (DEX-Sévo 25 % contre Sévo 25 %). Les taux de cytokines pro- et anti-inflammatoires ont tous deux été plus bas dans le groupe DEX-Sévo que dans le groupe Sévo. Néanmoins, les ratios d'interleukines (IL) IL-6/IL-10 (différence entre médianes, 5,8; IC à 95 %, 1,8 à 10,0; P = 0,012) et IL-8/IL-10 (différence des médianes, 0,8; IC à 95 %, 0,2 à 1,3; P = 0,007) ont été plus élevés dans le groupe DEX-Sévo que dans le groupe Sévo indiquant un équilibre des cytokines pro-inflammatoires dans le groupe DEX-Sévo. Les taux de norépinéphrine et d'épinéphrine ont été inférieurs dans le groupe DEX-Sévo que dans le groupe Sévo (P < 0,001 pour les deux). CONCLUSIONS: La dexmédétomidine peropératoire a réduit la survenue de l'agitation au réveil, mais pas du delirium postopératoire chez des patients subissant une chirurgie thoracique. La dexmédétomidine a semblé interférer sur la survenue de l'agitation par le biais des catécholamines, mais pas par un effet anti-inflammatoire. Enregistrement de l'essai clinique Service d'information sur la recherche clinique (KCT 0001877); enregistré le 7 avril 2016.

K-Sample comparisons using propensity analysis.

In this paper, we investigate K-group comparisons on survival endpoints for observational studies. In clinical databases for observational studies, treatment for patients are chosen with probabilities varying depending on their baseline characteristics. This often results in noncomparable treatment groups because of imbalance in baseline characteristics of patients among treatment groups. In order to overcome this issue, we conduct propensity analysis and match the subjects with similar propensity scores across treatment groups or compare weighted group means (or weighted survival curves for censored outcome variables) using the inverse probability weighting (IPW). To this end, multinomial logistic regression has been a popular propensity analysis method to estimate the weights. We propose to use decision tree method as an alternative propensity analysis due to its simplicity and robustness. We also propose IPW rank statistics, called Dunnett-type test and ANOVA-type test, to compare 3 or more treatment groups on survival endpoints. Using simulations, we evaluate the finite sample performance of the weighted rank statistics combined with these propensity analysis methods. We demonstrate these methods with a real data example. The IPW method also allows us for unbiased estimation of population parameters of each treatment group. In this paper, we limit our discussions to survival outcomes, but all the methods can be easily modified for any type of outcomes, such as binary or continuous variables.

Paravertebral Block Does Not Reduce Cancer Recurrence, but Is Related to Higher Overall Survival in Lung Cancer Surgery: A Retrospective Cohort Study.

BACKGROUND: Postoperative analgesic methods are suggested to have an impact on long-term prognosis after cancer surgery through opioid-induced immune suppression. We hypothesized that regional analgesia that reduces the systemic opioid requirement would be related to lower cancer recurrence and higher overall survival compared to intravenous patient-controlled analgesia (PCA) for lung cancer surgery. METHODS: Records for all patients who underwent open thoracotomy for curative resection of primary lung cancer between 2009 and 2013 in a tertiary care hospital were retrospectively analyzed. Patients were divided by postoperative analgesic methods: PCA (n = 574), thoracic epidural analgesia (TEA, n = 619), or paravertebral block (PVB, n = 536). Overall and recurrence-free survivals were compared among 3 analgesic methods via a multivariable Cox proportional hazard model and a log-rank test after adjusting confounding factors using propensity score matching (PSM). RESULTS: Analgesic method was associated with overall survival (P= .0015; hazard ratio against TEA [95% confidence intervals]: 0.58 [0.39-0.87] for PCA, 0.60 [0.45-0.79] for PVB). After confounder adjustment using PSM, PVB showed higher overall survival than PCA (log-rank P= .0229) and TEA (log-rank P= .0063) while PCA and TEA showed no difference (log-rank P= .6). Hazard ratio for PVB was 0.66 [0.46-0.94] against PCA and 0.65 [0.48-0.89] against TEA after PSM. However, there was no significant association between the analgesic methods and recurrence-free survival (P= .5; log-rank P with PSM = .5 between PCA and TEA, .5 between PCA and PVB, .1 between TEA and PVB). CONCLUSIONS: Pain-control methods are not related to cancer recurrence. However, PVB may have a beneficial effect on overall survival of patients with lung cancer.

Stroke Volume Variation and Pulse Pressure Variation Are Not Useful for Predicting Fluid Responsiveness in Thoracic Surgery.

BACKGROUND: Stroke volume variation (SVV) and pulse pressure variation (PPV) are used as indicators of fluid responsiveness, but little is known about the usefulness of these dynamic preload indicators in thoracic surgery, which involves an open thoracic cavity and 1-lung ventilation (OLV). Therefore, we investigated whether SVV and PPV could predict fluid responsiveness, and whether the thresholds of these parameters should be adjusted for thoracic surgery. METHODS: This was a prospective, controlled study conducted in a tertiary care center. Eighty patients scheduled for an elective lobectomy requiring OLV were included (n = 40, video-assisted thoracoscopic surgery (VATS); n = 40, open thoracotomy). Twenty minutes after opening the thoracic cavity, 7 mL/kg hydroxyethyl starch was administered for 30 minutes. Various hemodynamic parameters were measured before and after fluid challenge. RESULTS: Among the 80 patients enrolled in this study, 37% were fluid responders (increase in stroke volume index ≥10%). SVV before fluid challenge was not different between nonresponders and responders (mean ± SD: 7.1 ± 2.7% vs 7.4 ± 2.6%, P = .68). This finding was true regardless of whether the surgery involved open thoracotomy or VATS. PPV before fluid challenge showed the difference between nonresponders and responders (mean ± SD: 6.9 ± 3.0% vs 8.4 ± 3.2%; P = .045); however, the sensitivity and specificity of the threshold value (PPV = 7%) were low (58% and 62%, respectively) and the area under the receiver operating characteristics curve was only 0.63 (95% confidence interval, 0.52-0.74; P = .041). CONCLUSIONS: Dynamic preload indicators are not useful for predicting fluid responsiveness in VATS or open thoracic surgery.

The effect of fluvastatin on cardiac fibrosis and angiotensin-converting enzyme-2 expression in glucose-controlled diabetic rat hearts.

Independently of the lipid-lowering effects, statin has been reported to attenuate the development of diabetic cardiomyopathy. However, the effect of statin in glucose-controlled diabetic condition has not been demonstrated. We evaluated the effect of fluvastatin on cardiac function, fibrosis, and angiotensin-converting enzyme-2 (ACE2) expression in glucose-controlled diabetic rats. Male Wistar rats were randomly divided into four groups: control (Group C), diabetes (Group D), diabetes with insulin (Group I), and diabetes with insulin and fluvastatin (Group I+F). Diabetes was induced by a single injection of streptozotocin (65 mg/kg). After 8 weeks, the hearts were extracted following echocardiographic evaluation. Cardiac fibrosis was analyzed using Masson's trichrome stain. Collagens I and III and ACE2 expressions were evaluated by immunohistochemistry and western blot. Group D showed reduced cardiac systolic function compared to the other groups (all P < 0.05). However, diastolic function estimated by E/A ratio was significantly decreased in groups D and I (median: 0.88 and 1.45, respectively) compared to groups C and I+F (2.97 and 2.15) (all P < 0.05). Cardiac fibrosis was more severe in groups D and I than in groups C and I+F (all P < 0.05) on Masson's trichrome stain. On immunohistochemistry, ACE2 expression was significantly decreased only in group D (all P < 0.05). However, collagen I and III showed higher expressions in group D compared to groups C and I+F while no significant difference was observed compared with group I (all P < 0.05). On western blot, collagen I and ACE2 expressions in group D (median: 1.78 and 0.35, respectively) were significantly different from groups C (references: 1) and I+F (0.76 and 1.21) (all P < 0.05), but not from group I (1.19 and 0.92). Our study suggested a combination of fluvastatin and insulin would be more effective than insulin alone in diabetic hearts. However, the exact mechanism remains to be elucidated.

The Risk of Acute Kidney Injury from Fluid Restriction and Hydroxyethyl Starch in Thoracic Surgery.

BACKGROUND: Fluid is restricted in thoracic surgery to reduce acute lung injury, and hydroxyethyl starches (HES) are often administered to reduce fluid amount. This strategy may contribute to the development of acute kidney injury (AKI). We evaluated the incidence, risk factors, and prognosis of AKI in thoracic surgery. We especially focused on whether fluid restriction/HES administration increased AKI. METHODS: This is a retrospective study of patients undergoing thoracic surgery in a tertiary care academic center. Postoperative AKI was diagnosed within 72 hours after surgery based on the Acute Kidney Injury Network criteria. Demographic, intraoperative, and postoperative data were compared between non-AKI and AKI groups. Logistic regression was used to model the association between risk factors and AKI. RESULTS: Final analysis included 1442 patients. Of these, 74 patients developed AKI (5.1%). Crystalloid restriction (≤3 mL·kg·h) was unrelated to AKI, regardless of preoperative renal functions (odds ratio [OR], 0.5; 95% confidence interval [CI] 0.2-1.4). AKI occurred more often when HES were administered to the patients with decreased renal function (OR, 7.6; 95% CI, 1.5-58.1) or having >2 risk factors with normal renal function (OR, 7.2; 95% CI, 3.6-14.1). Multivariate analysis revealed several risk factors: angiotensin-converting enzyme inhibitor/angiotensin receptor blockers, open thoracotomy, pneumonectomy/esophagectomy, diabetes mellitus, cerebrovascular disease, low albumin level, and decreased renal function. CONCLUSIONS: Fluid restriction neither increased nor was a risk factor for AKI. HES should be administered with caution in high-risk patients undergoing thoracic surgery.