The Role of Recipient Thyroid Hormone Supplementation in Primary Graft Dysfunction After Heart Transplantation: A Propensity-Adjusted Analysis.

OBJECTIVES: To investigate whether recipient administration of thyroid hormone (liothyronine [T3]) is associated with reduced rates of primary graft dysfunction (PGD) after orthotopic heart transplantation. DESIGN: Retrospective cohort study. SETTING: Single-center, university hospital. PARTICIPANTS: Adult patients undergoing orthotopic heart transplantation. INTERVENTIONS: A total of 609 adult heart transplant recipients were divided into 2 cohorts: patients who did not receive T3 (no T3 group, from 2009 to 2014), and patients who received T3 (T3 group, from 2015 to 2019). Propensity-adjusted logistic regression was performed to assess the association between T3 supplementation and PGD. MEASUREMENTS AND MAIN RESULTS: After applying exclusion criteria and propensity-score analysis, the final cohort included 461 patients. The incidence of PGD was not significantly different between the groups (33.9% no T3 group v 40.8% T3 group; p = 0.32). Mortality at 30 days (3% no T3 group v 2% T3 group; p = 0.53) and 1 year (10% no T3 group v 12% T3 group; p = 0.26) were also not significantly different. When assessing the severity of PGD, there were no differences in the groups' rates of moderate PGD (not requiring mechanical circulatory support other than an intra-aortic balloon pump) or severe PGD (requiring mechanical circulatory support other than an intra-aortic balloon pump). However, segmented time regression analysis revealed that patients in the T3 group were less likely to develop severe PGD. CONCLUSIONS: These findings indicated that recipient single-dose thyroid hormone administration may not protect against the development of PGD, but may attenuate the severity of PGD.

Perioperative Fluid Management.

The medical complexity of the geriatric patients has been steadily rising. Still, as outcomes of surgical procedures in the elderly are improving, centers are pushing boundaries. There is also a growing appreciation of the importance of perioperative fluid management on postoperative outcomes, especially in the elderly. Optimal fluid management in this cohort is challenging due to the combination of age-related physiological changes in organ function, increased comorbid burden, and larger fluid shifts during more complex surgical procedures. The current state-of-the-art approach to fluid management in the perioperative period is outlined.

An Unusual Cause of End-Tidal Carbon Dioxide Rise During One-Lung Ventilation.

A relatively common problem that may arise during one-lung ventilation is elevation of end-tidal carbon dioxide (ETCO2), which has several potential etiologies. This case report describes a 69-year-old woman with carcinoid tumor undergoing a robotic left lower lobectomy complicated by an acute rise in ETCO2 during one-lung ventilation, without an immediately identifiable cause. Thorough evaluation revealed CO2 leak through an open bronchial lumen resulting in an artificially high ETCO2 reading. This case report demonstrates the importance of performing a comprehensive assessment during acute changes in ETCO2 while also considering changes in the surgical field, which may contribute to these findings.

Anesthetics to Prevent Lung Injury in Cardiac Surgery: A Randomized Controlled Trial.

OBJECTIVES: To investigate if sevoflurane based anesthesia is superior to propofol in preventing lung inflammation and preventing postoperative pulmonary complications. DESIGN: Randomized controlled trial. SETTING: Single tertiary care university hospital. PARTICIPANTS: Forty adults undergoing cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized in a 1:1 ratio to anesthetic maintenance with sevoflurane or propofol. MEASUREMENTS AND MAIN RESULTS: Blood and bronchoalveolar lavage fluid was sampled before and after bypass to measure pulmonary inflammation using a biomarker panel. The change in bronchoalveolar lavage concentration of tumor necrosis factor alpha (TNFα) was the primary outcome. Secondary outcomes included lung inflammation defined as changes in other biomarkers and postoperative pulmonary complications. There were no significant differences between groups in the change in bronchoalveolar lavage TNFα concentration (median [IQR] change, 17.24 [1.11-536.77] v 101.51 [1.47-402.84] pg/mL, sevoflurane v propofol, p = 0.31). There was a significantly lower postbypass concentration of plasma interleukin 8 (median [IQR], 53.92 [34.5-55.91] v 66.92 [53.03-94.44] pg/mL, p = 0.04) and a significantly smaller postbypass increase in the plasma receptor for advanced glycosylation end products (median [IQR], 174.59 [73.59-446.06] v 548.22 [193.15-852.39] pg/mL, p = 0.03) in the sevoflurane group compared with propofol. The incidence of postoperative pulmonary complications was 100% in both groups, with high rates of pleural effusion (17/18 [94.44%] v 19/22 [86.36%], p = 0.39) and hypoxemia (16/18 [88.88%] v 22/22 [100%], p = 0.11). CONCLUSIONS: Sevoflurane anesthesia during cardiac surgery did not consistently prevent lung inflammation or prevent postoperative pulmonary complications compared to propofol. There were significantly lower levels of 2 plasma biomarkers specific for lung injury and inflammation in the sevoflurane group.

Bleeding and thrombotic events in adults supported with venovenous extracorporeal membrane oxygenation: an ELSO registry analysis.

PURPOSE: This study aimed at analyzing the prevalence, mortality association, and risk factors for bleeding and thrombosis events (BTEs) among adults supported with venovenous extracorporeal membrane oxygenation (VV-ECMO). METHODS: We queried the Extracorporeal Life Support Organization registry for adults supported with VV-ECMO from 2010 to 2017. Multivariable logistic regression modeling was used to assess the association between BTEs and in-hospital mortality and the predictors of BTEs. RESULTS: Among 7579 VV-ECMO patients meeting criteria, 40.2% experienced ≥ 1 BTE. Thrombotic events comprised 54.9% of all BTEs and were predominantly ECMO circuit thrombosis. BTE rates decreased significantly over the study period (p < 0.001). The inpatient mortality rate was 34.9%. Bleeding events (1.69 [1.49-1.93]) were more strongly associated with in-hospital mortality than thrombotic events (1.23 [1.08-1.41]) p < 0.01 for both. The BTEs most strongly associated with mortality were ischemic stroke (4.50 [2.55-7.97]) and medical bleeding, including intracranial (5.71 [4.02-8.09]), pulmonary (2.02 [1.54-2.67]), and gastrointestinal (1.54 [1.2-1.98]) hemorrhage, all p < 0.01. Risk factors for bleeding included acute kidney injury and pre-ECMO vasopressor support and for thrombosis were higher weight, multisite cannulation, pre-ECMO arrest, and higher PaCO2 at ECMO initiation. Longer time on ECMO, younger age, higher pH, and earlier year of support were associated with bleeding and thrombosis. CONCLUSIONS: Although decreasing over time, BTEs remain common during VV-ECMO and have a strong, cumulative association with in-hospital mortality. Thrombotic events are more frequent, but bleeding carries a higher risk of inpatient mortality. Differential risk factors for bleeding and thrombotic complications exist, raising the possibility of a tailored approach to VV-ECMO management.

Renal-Resistive Index for Prediction of Acute Kidney Injury in the Setting of Aortic Insufficiency.

Acute kidney injury (AKI) is a common postoperative complication after cardiac surgery with cardiopulmonary bypass (CPB), and leads to significant morbidity, mortality, and cost. Although early recognition and management of AKI may reduce the burden of renal disease, reliance on serum creatinine accumulation to confidently diagnose it leads to a significant and important delay (up to 48 hours). Hence, a search for earlier AKI biomarkers is warranted. The renal-resistive index (RRI) is a promising early AKI biomarker that reflects intrarenal arterial pulsatility as reflected by the peak systolic and end-diastolic blood velocities divided by the peak systolic velocity. During cardiac surgery, post-CPB elevation of RRI is correlated with renal injury. The RRI is influenced by intrarenal and extrarenal factors, as well as different hemodynamic states. Understanding its limitations may increase its usefulness as an early AKI biomarker. For example, tachycardia or aortic stenosis typically results in a lower RRI, whereas bradycardia or increased systemic pulse pressure (as seen with aortic insufficiency) are associated with a higher RRI, unrelated to any intrarenal effects. In this E-Challenge, the authors present two cases in which the RRI was used to evaluate a patient's risk of developing AKI.

Development of an Instrument for Preoperative Prediction of Adverse Discharge in Patients Scheduled for Cardiac Surgery.

OBJECTIVE: Inability of home discharge occurs in nearly a third of patients undergoing cardiac surgery and is associated with increased mortality. The authors aimed to evaluate the incidence and risk factors for adverse discharge disposition (ADD) after cardiac surgery and develop a prediction tool for preoperative risk assessment. DESIGN: This retrospective cohort study included adult patients undergoing cardiac surgery between 2010 and 2018. The primary outcome was ADD, defined as in-hospital mortality, discharge to a skilled nursing facility, or transfer to a long-term care hospital. The authors created a prediction tool using stepwise backward logistic regression and used 5-fold and leave-one-out cross-validation. SETTING: University hospital network. PARTICIPANTS: Adult patients living at home prior to surgery, who underwent coronary artery bypass grafting and/or valve procedures at the authors' institution. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 3,760 patients were included in the final study cohort. The observed rate of ADD was 33.3%. The prediction model showed good discrimination and accuracy, with C-statistic of 0.78 (95% confidence interval [CI] 0.76-0.79) and unmodified Brier score of 0.177 (reliability 0.001). The final model comprised 14 predictors. Patients who experienced ADD were more likely to be older, of female sex, to have had higher length of hospital stay prior to surgery, and to have undergone emergency surgery. CONCLUSIONS: The authors present an instrument for prediction of loss of the ability to live independently in patients undergoing cardiac surgery. The authors' score may be useful in identifying high-risk patients such that earlier coordination of care can be initiated in this vulnerable patient population.

Interventional Pulmonology: A Brave New World.

Interventional pulmonology is a dynamic and evolving field in respiratory medicine. Advances have improved the ability to diagnose and manage diseases of the airways. A shift toward early detection of malignant disease has generated a focus on innovative diagnostic techniques. With patient populations living longer with malignant and benign diseases, the role for interventional bronchoscopy has grown. In cancer groups, novel immunotherapies have improved the prospects of clinical outcomes and reignited a focus on optimizing patient performance status to enable access to anticancer therapy. This review discusses current and emerging diagnostic modalities and therapeutic approaches available to manage airway diseases.

Perioperative Considerations for Tracheostomies in the Era of COVID-19.

The morbidity, mortality, and blistering pace of transmission of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented worldwide health crisis. Coronavirus disease 2019 (COVID-19), the disease produced by SARS-CoV-2 infection, is remarkable for persistent, severe respiratory failure requiring mechanical ventilation that places considerable strain on critical care resources. Because recovery from COVID-19-associated respiratory failure can be prolonged, tracheostomy may facilitate patient management and optimize the use of mechanical ventilators. Several important considerations apply to plan tracheostomies for COVID-19-infected patients. After performing a literature review of tracheostomies during the severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS) outbreaks, we synthesized important learning points from these experiences and suggested an approach for perioperative teams involved in these procedures during the COVID-19 pandemic. Multidisciplinary teams should be involved in decisions regarding timing and appropriateness of the procedure. As the theoretical risk of disease transmission is increased during aerosol-generating procedures (AGPs), stringent infectious precautions are warranted. Personal protective equipment (PPE) should be available and worn by all personnel present during tracheostomy. The number of people in the room should be limited to those absolutely necessary. Using the most experienced available operators will minimize the total time that staff is exposed to an infectious aerosolized environment. An approach that secures the airway in the safest and quickest manner will minimize the time any part of the airway is open to the environment. Deep neuromuscular blockade (train-of-four ratio = 0) will facilitate surgical exposure and prevent aerosolization due to patient movement or coughing. For percutaneous tracheostomies, the bronchoscopist should be able to reintubate if needed. Closed-loop communication must occur at all times among members of the team. If possible, after tracheostomy is performed, waiting until the patient is virus-free before changing the cannula or downsizing may reduce the chances of health care worker infection. Tracheostomies in COVID-19 patients present themselves as extremely high risk for all members of the procedural team. To mitigate risk, systematic meticulous planning of each procedural step is warranted along with strict adherence to local/institutional protocols.

Automated Spectral Doppler Profile Tracing.

OBJECTIVE: The authors hypothesized that automated tracings of both pulsed wave (PW) and continuous wave (CW) Doppler correlate well with manual measurements performed by an experienced echocardiographer. DESIGN: The authors performed a retrospective analysis of spectral Doppler profile measurements performed by automated software and an echocardiographer. SETTING: University hospital, single institution. PARTICIPANTS: The authors reviewed transesophageal echocardiographic examinations from patients undergoing transcatheter aortic valve (AV) replacement procedures at their institution. INTERVENTIONS: No interventions were performed solely for research purposes. MEASUREMENTS AND MAIN RESULTS: PW and CW spectral envelopes at the left ventricular outflow tract (LVOT) and AV were analyzed. Blinded, a board-certified echocardiographer performed manual measurements of the identical spectral envelopes. Peak velocities, mean gradients, and velocity time integrals (VTI) were collected. A total of 33 PW as well as 33 CW Doppler spectral envelopes were evaluated. There was no significant difference between the measurements provided by the automated software and manual tracings. LVOT PW VTI automated versus manual: 18.2 cm versus 15.9 cm, p = 0.11. AV CW VTI automated versus manual: 65.8 cm versus 64.8 cm, p = 0.90. AV CW mean gradient automated versus manual: 24.3 mmHg versus 23.4 mmHg, p = 0.84. AV CW peak velocity automated versus manual: 3.00 m/s versus 2.98 m/s, p = 0.93. Correlation coefficients were all above 0.9. CONCLUSIONS: Automated measurements of peak velocities, mean gradients, and VTI of spectral Doppler correlate closely with manual measurements performed by an experienced echocardiographer.

Endothelial Function Is Preserved in Veins Harvested by Either Endoscopic or Surgical Techniques.

BACKGROUND: Endoscopic vein harvest for lower extremity arterial bypass grafting has been questioned due to concern for endothelial damage during procurement. We sought to compare nitric oxide (NO)-mediated endothelial-dependent relaxation (EDR) in vein segments harvested using open surgical techniques (OH) versus endoscopic vein harvest (EH) techniques. METHODS: Saphenous vein segments were harvested for lower extremity bypass, and a single, minimally handled section of saphenous vein, free of branches, was taken from the end of the graft. Four 4-mm venous ring segments were then cut and mounted on force transducers. Segments were mounted in 37° oxygenated Krebs-Henseleit solution and maximally contracted using KCl. Individual ring segments that did not react to KCl were excluded from the study. Norepinephrine (NE) was used to achieve submaximal contraction. EDR was determined using increasing concentrations of bradykinin (BDK). Endothelial-independent relaxation (EIR) was confirmed using sodium nitroprusside. Two-way analysis of variance (ANOVA) was used to analyze differences between harvest techniques across BDK concentration and a Student's t-test was used to analyze single comparisons. RESULTS: Vein segments harvested from patients (n = 13) led to 28 viable rings that exhibited a positive reaction to KCl (11 rings; 5 patients EH vs. 17 rings; 8 patients OH). Both vein groups achieved moderate relaxation to maximal BDK concentration, [10-6 M]; (49.5% EH vs. 40.55% OH, P = 0.270). Analysis by 2-way ANOVA for mean % relaxation for BDK concentration [10-11-10-6 M] showed improved EDR in EH samples compared with OH (P = 0.029). Mean nitrite/nitrate (NO(x)) tissue bath concentration measurements post-BDK were 139.8 nM (EH) vs. 97.2 nM (OH; P = 0.264). Histology and positive factor VIII immunohistochemistry staining provided evidence for the presence of intact endothelium in our sample segments. EIR was preserved and was similar in the two groups. CONCLUSIONS: Endothelial function is preserved when utilizing endoscopic harvesting techniques. The advantages of minimally invasive vein procurement for lower extremity bypass can be obtained without concern for damaging venous endothelium.

Simulation of carotid artery stenting reduces training procedure and fluoroscopy times.

OBJECTIVE: Outcomes from carotid artery stenting (CAS) are related to experience and technical expertise of the operator. Simulation of CAS may enhance clinical proficiency. We interrogated the impact of endovascular simulation of CAS procedures in operators who are at various stages of training. METHODS: Twelve trainees (students [n = 4]; junior surgery residents, postgraduate year [PGY] 1-3 [n = 4]; and senior surgery residents or fellows, PGY 4-7 [n = 4]) were apprised of characteristics of an endovascular simulator and CAS procedures. This was followed by four independent sessions that were assessed for objective measures including procedure and fluoroscopy times and contrast agent use. A qualitative analysis grading steps of CAS by two observers using a Likert scale was performed. One-way analysis of variance and paired t-tests were employed for data analysis. RESULTS: For all participants (n = 12), procedure times (mean, 920 ± 279 seconds for the first session vs 454 ± 156 seconds for the fourth session; P < .01; confidence interval [CI], 315-621) and fluoroscopy cumulative times (mean, 421 ± 230 seconds for the first session vs 222 ± 102 seconds for the fourth session; P < .01; CI, 78-285) decreased with progression of cases. Students and PGY 1-3 residents decreased their procedure times significantly in comparison of initial and final sessions (P < .05 and P < .01, respectively). For all groups, fluoroscopy cumulative times were reduced, and this decrement was significant in the PGY 1-3 cohort (mean, 444 ± 8 seconds for the first session vs 265 ± 51 seconds for the fourth session; P < .01; CI, 81-276). Initial CAS procedure times were significantly different between groups (P < .05), but this was observed to resolve by the final case at study completion. Qualitatively, the Likert scores of students and PGY 1-3 residents significantly improved with case repetition, specifically in the following steps: (1) cannulation of common carotid artery and (2) sizing and deployment of embolic protection device. Senior operators (PGY 4-7) demonstrated consistently better performance overall with minimal change in scoring with case repetition. CONCLUSIONS: Practice leads to improvements in endovascular simulator procedure and fluoroscopy times, especially for more novice trainees. Initial operator performance gaps can be approximated with a few sessions to expected proficiency. Incorporation of endovascular simulators in residency training may assist in shortening the learning curve in rarer endovascular procedures.

Dextran or Saline Can Replace Contrast for Intravascular Optical Coherence Tomography in Lower Extremity Arteries.

PURPOSE: To examine the hypothesis that alternative flush media could be used for lower extremity optical coherence tomography (OCT) imaging in long lesions that would normally require excessive use of contrast. METHODS: The OPTical Imaging Measurement of Intravascular Solution Efficacy (OPTIMISE) trial was a single-center, prospective study (ClinicalTrials.gov identifier NCT01743872) that enrolled 23 patients (mean age 68±11 years; 14 men) undergoing endovascular intervention involving the superficial femoral artery. Four flush media (heparinized saline, dextran, carbon dioxide, and contrast) were used in succession in random order for each image pullback. Quality was defined as ≥270° visualization of vessel wall layers from each axial image. Mean proportions (± standard deviation) of image quality for each flush medium were assessed using 1-way analysis of variance and are reported with the 95% confidence intervals (CI). RESULTS: Four OCT catheters failed, leaving 19 patients who completed the OCT imaging protocol; from this cohort, 51 highest quality runs were selected for analysis. Average vessel diameter was 3.99±1.01 mm. OCT imaging allowed 10- to 15-µm resolution of the lumen border, with diminishing quality as vessel diameter increased. Plaque characterization revealed fibrotic lesions. Mean proportions of image quality were dextran 87.2%±12% (95% CI 0.81 to 0.94), heparinized saline 74.3%±24.8% (95% CI 0.66 to 0.93), contrast 70.1%±30.5% (95% CI 0.52 to 0.88), and carbon dioxide 10.0%±10.4% (95% CI 0.00 to 0.26). Dextran, saline, and contrast provided better quality than carbon dioxide (p<0.001). CONCLUSION: OCT is feasible in peripheral vessels <5 mm in diameter. Dextran or saline flush media can allow lesion characterization, avoiding iodinated contrast. Carbon dioxide is inadequate for peripheral OCT imaging. Axial imaging may aid in enhancing durability of peripheral endovascular interventions.

Endovascular Simulation Leads to Efficiency and Competence in Thoracic Endovascular Aortic Repair Procedures.

OBJECTIVE: Endovascular interventions such as thoracic endovascular aortic repair (TEVAR) have largely replaced invasive open procedures, and have been demonstrated to be effective in treating patients. Our study used endovascular simulation to assess the effect of TEVAR rehearsal on surgical trainees at different levels in training. DESIGN: Participants were oriented on an endovascular simulator and subsequently a simulated TEVAR was performed during 4 separate sessions over a 1-month period. Metrics included total procedure/fluoroscopy time and volume of contrast used. Likert scale qualitative analysis evaluated participant׳s skills involving major procedural steps. Analysis of data across cohorts included 1-way analysis of variance, Kruskal-Wallis, and paired t-tests. SETTING: All data were collected at University Hospitals-Case Medical Center, Cleveland, OH. PARTICIPANTS: In all, 12 trainees in 3 cohorts (student, surgery resident postgraduate year [PGY] 1-3, surgery resident/fellow PGY 4-7, n = 4 each) were recruited. RESULTS: All trainees reduced total procedure time (mean = 537 ± 148 vs 269 ± 66s, first session vs fourth, P < 0.05, CI: 195-341) and fluoroscopy time (mean = 201 ± 74 vs 110 ± 37s, P < 0.05, CI: 51-132) with TEVAR case progression. The student cohort decreased procedure time from 551 ± 84s to 313 ± 65s (P < 0.05, CI: 189-287) whereas PGYs 1 to 3 decreased procedure time from 591 ± 149s to 264 ± 29s (P < 0.05, CI: 113-541). Use of contrast decreased over time, but the difference was not significant. Participants acquired proficiency after a few runs in most steps of the procedure. The average qualitative score for all groups combined improved significantly (P < 0.03). PGY 4 to 7 trainees had higher technical scores but this was not statistically significant. The initial gap in junior vs senior trainee performance narrowed after a few practice sessions in all aspects evaluated. CONCLUSIONS: TEVAR rehearsal on an endovascular simulator can reduce overall procedure and fluoroscopy time, independent of trainee skill level or experience, as well as improve subjective measures of technical success. Further studies are needed to compare simulator performance to outcomes in live cases.