Continuous Right Ventricular Pressure Monitoring in Cardiac Surgery.

OBJECTIVE: Right ventricular (RV) dysfunction in cardiac surgery can lead to RV failure, which is associated with increased morbidity and mortality. Abnormal RV function can be identified using RV pressure monitoring. The primary objective of the study is to determine the proportion of patients with abnormal RV early to end-diastole diastolic pressure gradient (RVDPG) and abnormal RV end-diastolic pressure (RVEDP) before initiation and after cardiopulmonary bypass (CPB) separation. The secondary objective is to evaluate if RVDPG before CPB initiation is associated with difficult and complex separation from CPB, RV dysfunction, and failure at the end of cardiac surgery. DESIGN: Prospective study. SETTING: Tertiary care cardiac institute. PARTICIPANTS: Cardiac surgical patients. INTERVENTION: Cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Automated electronic quantification of RVDPG and RVEDP were obtained. Hemodynamic measurements were correlated with cardiac and extracardiac parameters from transesophageal echocardiography and postoperative complications. Abnormal RVDPG was present in 80% of the patients (n = 105) at baseline, with a mean RVEDP of 14.2 ± 3.9 mmHg. Patients experienced an RVDPG > 4 mmHg for a median duration of 50.2% of the intraoperative period before CPB initiation and 60.6% after CPB separation. A total of 46 (43.8%) patients had difficult/complex separation from CPB, 18 (38.3%) patients had RV dysfunction, and 8 (17%) had RV failure. Abnormal RVDPG before CPB was not associated with postoperative outcome. CONCLUSION: Elevated RVDPG and RVEDP are common in cardiac surgery. RVDPG and RVEDP before CPB initiation are not associated with RV dysfunction and failure but can be used to diagnose them.

Perioperative Doppler ultrasound assessment of portal vein flow pulsatility in high-risk cardiac surgery patients: a multicentre prospective cohort study.

BACKGROUND: Portal vein Doppler ultrasound pulsatility measured by transoesophageal echocardiography is a marker of the haemodynamic impact of venous congestion in cardiac surgery. We investigated whether the presence of abnormal portal vein flow pulsatility is associated with a longer duration of invasive life support and postoperative complications in high-risk patients. METHODS: In this multicentre cohort study, pulsed-wave Doppler ultrasound assessments of portal vein flow were performed during anaesthesia before initiation of cardiopulmonary bypass (before CPB) and after separation of cardiopulmonary bypass (after CPB). Abnormal pulsatility was defined as portal pulsatility fraction (PPF) ≥50% (PPF50). The primary outcome was the cumulative time in perioperative organ dysfunction (TPOD) requiring invasive life support during 28 days. Secondary outcomes included major postoperative complications. RESULTS: 373 patients, 71 (22.0%) had PPF50 before CPB and 77 (24.9%) after CPB. PPF50 was associated with longer duration of TPOD (median [inter-quartile range]; before CPB: 27 h [11-72] vs 19 h [8.5-42], P=0.02; after CPB: 27 h [11-61] vs 20 h [8-42], P=0.006). After adjusting for confounders, PPF50 before CPB showed significant association with TPOD. PPF50 after CPB was associated with a higher rate of major postoperative complications (36.4% vs 20.3%, P=0.006). CONCLUSIONS: Abnormal portal vein flow pulsatility before cardiopulmonary bypass was associated with longer duration of life support therapy after cardiac surgery in high-risk patients. Abnormal portal vein flow pulsatility after cardiopulmonary bypass separation was associated with a higher risk of major postoperative complications although this association was not independent of other factors. CLINICAL TRIAL REGISTRATION: NCT03656263.

Transgastric Abdominal Ultrasonography in Anesthesia and Critical Care: Review and Proposed Approach.

The use of transesophageal echocardiography (TEE) in the operating room and intensive care unit can provide invaluable information on cardiac as well as abdominal organ structures and function. This approach may be particularly useful when the transabdominal ultrasound examination is not possible during intraoperative procedures or for anatomical reasons. This review explores the role of transgastric abdominal ultrasonography (TGAUS) in perioperative medicine. We describe several reported applications using 10 views that can be used in the diagnosis of relevant abdominal conditions associated with organ dysfunction and hemodynamic instability in the operating room and the intensive care unit.

Canadian recommendations for training and performance in basic perioperative point-of-care ultrasound: recommendations from a consensus of Canadian anesthesiology academic centres.

Point-of-care ultrasound (POCUS) uses ultrasound at the bedside to aid decision-making in acute clinical scenarios. The increased use of ultrasound for regional anesthesia and vascular cannulation, together with more anesthesiologists trained in transesophageal echocardiography have contributed to the widespread use of POCUS in perioperative care. Despite the support of international experts, the practice of POCUS in perioperative care is variable as Canadian guidelines for anesthesiologists do not currently exist. Using a Delphi process of online surveys and a face-to-face national Canadian meeting, we developed a consensus statement for basic POCUS (bPOCUS) performance and training with a group of national experts from all Canadian universities. The group of experts consisted of 55 anesthesiologists from 12 Canadian universities considered local leaders in the field. An initial exploratory online survey of 47 statements was conducted. These statements were derived from previous generic guidelines or consensus conferences, or were based on current literature. Fourteen statements reached full consensus, 19 had 90-100% agreement, and 14 had less than 90% agreement. Eight new statements were proposed during the national meeting, and all statements without full agreement were discussed. A second online survey included 42 modified or new statements. From this second survey, 16 statements obtained full consensus, 39 had very good agreement, and one had good agreement. The final document includes 56 statements that define the scope of practice and necessary training for perioperative bPOCUS. The statements include five bPOCUS domains: cardiac, lung, airway, gastric, and abdomen. The use of bPOCUS is evolving and will play a significant role in perioperative medicine. This consensus statement aims to define a Canadian national standard on which curricula may be based. It also provides a framework to allow further development of bPOCUS in the perioperative setting.

RéSUMé: L'échographie ciblée (POCUS) utilise l'échographie au chevet des patients pour faciliter la prise de décisions dans les situations cliniques urgentes. L'utilisation accrue de l'échographie pour l'anesthésie régionale et la cannulation vasculaire, ainsi que l'augmentation du nombre d'anesthésologistes formés à l'échocardiographie transesophagienne, ont contribué à l'utilisation généralisée de l'échographie ciblée dans les soins périopératoires. Malgré son endossement par des experts internationaux, la pratique de l'échographie ciblée en soins périopératoires est variable, car il n'existe pas, à l'heure actuelle, de lignes directrices canadiennes destinées aux anesthésiologistes. À l'aide d'un processus Delphi de sondages en ligne et d'une réunion nationale canadienne en personne, un groupe d'experts nationaux provenant de toutes les universités canadiennes a élaboré une déclaration consensuelle pour la formation de base en et l'exécution de l'échographie ciblée (bPOCUS). Le groupe d'experts était composé de 55 anesthésiologistes issus de 12 universités canadiennes considérés comme des chefs de file locaux dans le domaine. Un premier sondage exploratoire en ligne comportant 47 énoncés a été réalisé. Ces énoncés étaient dérivés de lignes directrices antérieures ou de conférences consensuelles, ou étaient fondés sur la littérature actuelle. Quatorze énoncés ont obtenu un consensus complet, 19 ont atteint un taux de 90 à 100 %, et 14 ont obtenu moins de 90 % d'accord. Huit nouveaux énoncés ont été proposés au cours de la réunion nationale, et tous les énoncés n'ayant pas obtenu d'accord complet ont été discutés. Un deuxième sondage en ligne comprenait 42 énoncés modifiés ou nouveaux. Dans ce deuxième sondage, 16 énoncés ont obtenu un consensus total, 39 un très bon accord et un énoncé un bon accord. Le document final comporte 56 énoncés qui définissent le champ de pratique et la formation nécessaire pour l'échographie ciblée périopératoire de base. Les énoncés portent sur cinq domaines de l'échographie ciblée de base : échographie cardiaque, pulmonaire, des voies respiratoires, gastrique et abdominale. L'utilisation de l'échographie ciblée de base évolue et jouera un rôle important en médecine périopératoire. Cette déclaration consensuelle vise à définir une norme nationale canadienne sur laquelle les programmes d'études pourront s'appuyer. Elle fournit également un cadre pour encourager le développement ultérieur de l'échographie ciblée de base dans un contexte périopératoire.

Endovascular Vena Cavae Occlusion Technique in Minimally Invasive Tricuspid Valve Surgery in Patients With Previous Cardiac Surgery.

OBJECTIVES: The aim of the present study was to describe a bicaval endovascular occlusion technique in minimally invasive tricuspid valve (TV) surgery in patients with previous cardiac surgery. DESIGN: Case series. SETTING: Single tertiary university center. PARTICIPANTS: The study comprised ten patients. INTERVENTIONS: Endovascular occlusion of vena cavae for minimally invasive TV redo surgery. MEASUREMENTS AND MAIN RESULTS: Between 2008 and 2017, ten patients with previous cardiac surgery underwent TV minimally invasive surgery (repair or replacement; isolated or with concomitant procedures) using the Coda balloon catheter (Cook Medical, Bloomington, IN) to occlude both vena cavae. Data were collected retrospectively from electronic medical records. Superior and inferior vena cava occlusion with Coda balloon catheters was successful with no complications. The drainage of the vena cavae was optimal with excellent surgical exposure. Cardiopulmonary bypass time was 131 ± 119 minutes, with 30% of patients undergoing aortic clamping (two with a Chitwood clamp, one with an endoaortic balloon). Intensive care unit length of stay was 3.9 ± 2.7 days, and the in-hospital mortality rate was 30%. CONCLUSION: Bicaval endovascular occlusion of vena cavae is a feasible and effective technique in patients with previous cardiac surgery who are undergoing a minimally invasive TV procedure. The high mortality rate is associated with the inherent risk of a redo surgery involving the TV.

Preliminary Experience Using Diastolic Right Ventricular Pressure Gradient Monitoring in Cardiac Surgery.

OBJECTIVES: Right ventricular (RV) dysfunction in cardiac surgery is associated with increased mortality and morbidity and difficult separation from cardiopulmonary bypass (DSB). The primary objective of the present study was to describe the prevalence and characteristics of patients with abnormal RV diastolic pressure gradient (PG). The secondary objective was to explore the association among abnormal diastolic PG and DSB, postoperative complications, high central venous pressure (CVP), and high RV end-diastolic pressure (RVEDP). DESIGN: Retrospective and prospective validation study. SETTING: Tertiary care cardiac institute. PARTICIPANTS: Cardiac surgical patients (n=374) from a retrospective analysis (n=259) and a prospective validation group (n=115). INTERVENTION: RV pressure waveforms were obtained using a pulmonary artery catheter with a pacing port opened at 19 cm distal to the tip of the catheter. Abnormal RV diastolic PG was defined as >4 mmHg. Both elevated RVEDP and high CVP were defined as >16 mmHg. MEASUREMENTS AND MAIN RESULTS: From the retrospective and validation cohorts, 42.5% and 48% of the patients had abnormal RV diastolic PG before cardiac surgery, respectively. Abnormal RV diastolic PG before cardiac surgery was associated with higher EuroSCORE II (odds ratio 2.29 [1.10-4.80] v 1.62 [1.10-3.04]; p = 0.041), abnormal hepatic venous flow (45% v 29%; p = 0.038), higher body mass index (28.9 [25.5-32.5] v 27.0 [24.9-30.5]; p = 0.022), pulmonary hypertension (48% v 37%; p = 0.005), and more frequent DSB (32% v 19%; p = 0.023). However, RV diastolic PG was not an independent predictor of DSB, whereas RVEDP (odds ratio 1.67 [1.09-2.55]; p = 0.018) was independently associated with DSB. In addition, RV pressure monitoring indices were superior to CVP in predicting DSB. CONCLUSION: Abnormal RV diastolic PG is common before cardiac surgery and is associated with a higher proportion of known preoperative risk factors. However, an abnormal RV diastolic PG gradient is not an independent predictor of DSB in contrast to RVEDP.

The Role of Point-of-Care Ultrasound Monitoring in Cardiac Surgical Patients With Acute Kidney Injury.

The approach to the patient with acute kidney injury (AKI) after cardiac surgery involves multiple aspects. These include the rapid recognition of reversible causes, the accurate identification of patients who will progress to severe stages of AKI, and the subsequent management of complications resulting from severe renal dysfunction. Unfortunately, the inherent limitations of physical examination and laboratory parameter results are often responsible for suboptimal clinical management. In this review article, the authors explore how point-of-care ultrasound, including renal and extrarenal ultrasound, can be used to complement all aspects of the care of cardiac surgery patients with AKI, from the initial approach of early AKI to fluid balance management during renal replacement therapy. The current evidence is reviewed, including knowledge gaps and future areas of research.

Myocardial Protection in Minimally Invasive Mitral Valve Surgery: Retrograde Cardioplegia Alone Using Endovascular Coronary Sinus Catheter Compared With Combined Antegrade and Retrograde Cardioplegia.

OBJECTIVE: To compare myocardial protection with retrograde cardioplegia alone with antegrade and retrograde cardioplegia in minimally invasive mitral valve surgery (MIMS). DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: The authors studied 97 MIMS patients using retrograde cardioplegia alone and 118 MIMS patients using antegrade and retrograde cardioplegia. INTERVENTIONS: The data from patients admitted for MIMS using retrograde cardioplegia (MIMS retro) between 2009 to 2012 were compared with the data from patients undergoing MIMS with antegrade and retrograde cardioplegia (MIMS ante-retro) between 2006 and 2010 (control group). Cardioplegia in the MIMS retro group was delivered solely through an endovascular coronary sinus (CS) catheter positioned under echographic and fluoroscopic guidance. Antegrade and retrograde cardioplegia was used in the MIMS ante-retro group. Data regarding myocardial infarction (MI; creatine kinase Mb, troponin T, electrocardiogram), myocardial function, and hemodynamic stability were collected for comparison. MEASUREMENTS AND MAIN RESULTS: Adequate cardioplegia administration (CS pressure >30 mmHg and asystole) was attained in 74.2% of the patients with retrograde cardioplegia alone. In 23.7% of the patients, the addition of an antegrade cardioplegia was necessary. No difference was observed in the incidence of MI (0 MIMS retro v 1 for MIMS ante-retro, p = 0.3623), difficult separation from cardiopulmonary bypass, and postoperative malignant arrhythmia. No difference was found for maximal creatine kinase Mb (39.1 [28.0-49.1] v 37.9 [28.6-50.9]; p = 0.8299) and for maximal troponin T levels (0.39 [0.27-0.70] v 0.47 [0.32-0.79]; p = 0.1231) for MIMS retro and MIMS ante-retro, respectively. However, lactate levels in the MIMS retro group were significantly lower than in the MIMS ante-retro group (2.1 [1.4-3.05] v 2.4 [1.8-3.3], respectively; p = 0.0453). No difference was observed in duration of intensive care unit stay and death. MIMS retro patients had a shorter hospital stay (7.0 [6.0-8.0] v 8.0 [7.0-9.0] days; p = 0.0003). CONCLUSION: Retrograde cardioplegia administration alone provided comparable myocardial protection to antegrade and retrograde cardioplegia during MIMS, but was not sufficient to achieve asystole in one-fifth of patients.

Perioperative Right Ventricular Pressure Monitoring in Cardiac Surgery.

Right ventricular (RV) dysfunction is a cause of increased morbidity and mortality in both cardiac surgery and noncardiac surgery and in the intensive care unit. Early diagnosis of this condition still poses a challenge. The diagnosis of RV dysfunction traditionally is based on a combination of echocardiography, hemodynamic measurements, and clinical symptoms. This review describes the method of using RV pressure waveform analysis to diagnose and grade the severity of RV dysfunction. The authors describe the technique, optimal use, and pitfalls of this method, which has been used at the Montreal Heart Institute since 2002, and review the current literature on this method. The RV pressure waveform is obtained using a pulmonary artery catheter with the capability of measuring RV pressure by connecting a pressure transducer to the pacemaker port. The authors describe how RV pressure waveform analysis can facilitate the diagnosis of systolic and diastolic RV dysfunction, the evaluation of RV-arterial coupling, and help diagnose RV outflow tract obstruction. RV pressure waveform analysis also can be used to guide pharmacologic treatment and fluid resuscitation strategies for RV dysfunction.

Acute Right Ventricular Failure in Cardiac Surgery During Cardiopulmonary Bypass Separation: A Retrospective Case Series of 12 Years' Experience With Intratracheal Milrinone Administration.

OBJECTIVE: To report the authors' 12 years of experience with intratracheal milrinone administration and to assess the efficacy and limitations of intratracheal milrinone bolus administration for the treatment of unexpected acute right ventricular (RV) failure in patients undergoing cardiac surgery. DESIGN: Retrospective analysis. SETTING: Single-center university hospital. PARTICIPANTS: One hundred seventy-six patients (4.6%) undergoing on-pump cardiac surgery. INTERVENTIONS: Endotracheal tube administration of milrinone (5-mg bolus) after unexpected acute RV failure during separation from cardiopulmonary bypass (CPB) weaning. RV failure was defined as the simultaneous presence of all of the following criteria: (1) hemodynamic instability or difficult separation from CPB with associated elevated central venous pressure or abnormal RV pressure waveform, (2) >20% reduction of RV fractional area change from baseline evaluated by transesophageal echocardiography, and (3) anatomical visualization of impaired or absent RV wall motion by direct intraoperative visual inspection. MEASUREMENTS AND MAIN RESULTS: Intratracheal milrinone administration was found to improve RV failure in 109 patients (61.9%) whereas RV failure persisted in 67 patients (38.1%). Using a multiple logistic regression model, severely decreased left ventricular ejection fraction (<35% v >50%) (adjusted odds ratio [OR] 3.72; 95% confidence interval [CI] 1.2-11.3; p = 0.012), longer CPB time (adjusted OR 1.014; CI 1.01-1.02; p = 0.001) and elevated postoperative fluid balance (adjusted OR 1.39; CI 1.1-1.8; p = 0.02) were found to be significant predictors of persistent RV failure. CONCLUSION: Intratracheal instillation of milrinone was associated with clinical improvement of RV failure occurring during separation from CPB in almost two-thirds of patients. Factors limiting its therapeutic efficacy include severe left ventricular dysfunction, increased fluid balance, and long CPB time.

Transthoracic echocardiographic evaluation of the heart and great vessels.

PURPOSE: Transthoracic examination of the heart and great vessels is an essential skill that allows the anesthesiologist to evaluate cardiac function. In this article, we describe a pragmatic technique to obtain the essential views to evaluate normal or abnormal cardiac function and to appreciate great vessel anatomy and physiology. PRINCIPAL FINDINGS: The cardiac anatomy and function can be described using standard parasternal, apical, and subcostal views. These windows can also be used to assess the aorta, pulmonary artery, and vena cavae; however, other transthoracic and abdominal windows can be used to complete the evaluation of the great vessels. CONCLUSIONS: The integration of the echocardiographic information particularly from the heart and great vessels with the case story, physical examination, laboratory data, and other relevant clinical information should become the way of the future, and this will benefit the patients under our care.

Risk Factors for Radial-to-Femoral Artery Pressure Gradient in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass.

OBJECTIVE: To identify risk factors associated with radial-to-femoral pressure gradient during cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: This is a retrospective, observational study. SETTING: Single specialized cardiothoracic hospital in Montreal, Canada. PARTICIPANTS: Consecutive patients that underwent heart surgery with CPB between 2005 and 2015 (n = 435). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A radial-to-femoral pressure gradient occurred in 146 patients of the 435 patients (34%). Based on the 10,000 bootstrap samples, simple logistic regression models identified the 17 most commonly significant variables across the bootstrap runs. Using these variables, a backward multiple logistic model was performed on the original sample and identified the following independent variables: body surface area (m2) (odds ratio [OR] 0.08, 95% confidence interval [CI] 0.030-0.232), clamping time (minutes) (OR 1.01, 95% CI 1.007-1.018), fluid balance (for 1 liter) (OR 0.81, 95% CI 0.669-0.976), and preoperative hypertension (OR 1.801, 95% CI 1.131-2.868). CONCLUSION: A radial-to-femoral pressure gradient occurs in 34% of patients during cardiac surgery. Patients at risk seem to be of smaller stature, hypertensive, and undergo longer and more complex surgeries.

Clinical Significance of Portal Hypertension Diagnosed With Bedside Ultrasound After Cardiac Surgery.

BACKGROUND: Portal venous flow pulsatility detected by Doppler ultrasound is a sign of congestive heart failure in noncritically ill patients. The assessment of portal and splenic venous flows has never been reported in patients undergoing cardiac surgery. METHODS: This is a case series performed in patients undergoing cardiac surgery between February 2014 and February 2015 in which portal and/or splenic venous flows were assessed by the attending anesthesiologist during surgery or by the intensivist after surgery using transthoracic echography in 9 patients or transesophageal echocardiography in 5 patients. Data collection was done retrospectively by reviewing intraoperative and postoperative monitoring documents. The technique of assessment is detailed in this article. RESULTS: We report the abnormal portal and/or splenic venous flow pulsatility from 14 patients perioperatively. At the time of pulsatility detection, patients had a median cumulative fluid balance of 3.8 L (interquartile range: 0-4.6 L) and a median right atrial pressure of 14.0 mm Hg (interquartile range: 12.0-15.5 mm Hg). In some patients (4/14), signs of right ventricular dysfunction on echocardiography and/or right ventricular pressure monitoring were present. CONCLUSIONS: Doppler evaluation of portal and splenic venous flow using transthoracic echography and transesophageal echocardiography may represent a promising modality to assess end-organ venous congestion in cardiac surgery patients.

Intratracheal Milrinone Bolus Administration During Acute Right Ventricular Dysfunction After Cardiopulmonary Bypass.

OBJECTIVE: To evaluate intratracheal milrinone (tMil) administration for rapid treatment of right ventricular (RV) dysfunction as a novel route after cardiopulmonary bypass. DESIGN: Retrospective analysis. SETTING: Single-center study. PARTICIPANTS: The study comprised 7 patients undergoing cardiac surgery who exhibited acute RV dysfunction after cardiopulmonary bypass. INTERVENTIONS: After difficult weaning caused by cardiopulmonary bypass-induced acute RV dysfunction, milrinone was administered as a 5-mg bolus inside the endotracheal tube. MEASUREMENTS AND MAIN RESULTS: RV function improvement, as indicated by decreasing pulmonary artery pressure and changes of RV waveforms, was observed in all 7 patients. Adverse effects of tMil included dynamic RV outflow tract obstruction (2 patients) and a decrease in systemic mean arterial pressure (1 patient). CONCLUSIONS: tMil may be an effective, rapid, and easily applicable therapeutic alternative to inhaled milrinone for the treatment of acute RV failure during cardiac surgery. However, sufficiently powered clinical trials are needed to confirm these findings.

Low-Dose Versus High-Dose Tranexamic Acid Reduces the Risk of Nonischemic Seizures After Cardiac Surgery With Cardiopulmonary Bypass.

OBJECTIVE: The incidence of postoperative nonischemic seizures associated with the use of tranexamic acid (TXA) and the possibility of prevention with a low-dose regimen of TXA were evaluated. DESIGN: Retrospective study. SETTING: Tertiary care university hospital. PARTICIPANTS: A total of 12,195 patients who underwent cardiac surgical procedures under cardiopulmonary bypass (CPB) were evaluated. INTERVENTIONS: The files of every clinical seizure case diagnosed in the surgical intensive care unit between April 2006 and April 2014 were reviewed. Patients who experienced a postoperative seizure underwent a cerebral computed tomography scan to exclude an ischemic lesion. Dosage and type of antifibrinolytic used and surgery characteristics were retrieved from perfusion files. Low-dose TXA was defined as 1,000-mg bolus, 400-mg/h infusion, and 500 mg in CPB priming. High-dose TXA was defined as 30-mg/kg bolus, 15 mg/kg/h, and 2 mg/kg in CPB priming. RESULTS: No seizure was observed in the 886 patients who did not receive antifibrinolytics. A total of 98 clinical seizures (0.8%) were recorded in the intensive care unit, and ischemic cause was excluded in the majority of them after computed tomography scan results were reviewed (91 patients [93%]). Low-dose TXA was associated with fewer seizures than was high-dose TXA (46 of 7,452 cases [0.70%] v 34 of 2,190 cases [1.55%], respectively; p < 0.0001). Open-chamber cardiac surgery also was linked to a higher incidence of seizures compared with revascularization (80 of 6,662 [1.20%] and 11 of 5,533 [0.20%], respectively; p < 0.0001). CONCLUSIONS: Lower doses of TXA were associated with a lower incidence of nonischemic seizures compared with higher doses of the drug.

Transesophageal lung ultrasonography: a novel technique for investigating hypoxemia.

BACKGROUND: Acute deterioration in respiratory status commonly occurs in patients who cannot be transported for imaging studies, particularly during surgical procedures and in critical care settings. Transthoracic lung ultrasonography has been developed to allow rapid diagnosis of respiratory conditions at the bedside. Nevertheless, the thorax is not always accessible, especially in the perioperative setting. Transesophageal lung ultrasonography (TELU) can be used to circumvent this problem. PURPOSE: The aim of this narrative review is to provide a complete description of the TELU technique by summarizing the existing literature on the subject and describing our own experience that extrapolates from transthoracic lung ultrasonography. PRINCIPAL FINDINGS: The use of TELU can provide point-of-care real-time information for quickly establishing the etiology of acute hypoxemia. The transesophageal probe is placed in close proximity to the posterior regions of the lungs where lung consolidation and pleural effusions are most often seen; however, most of the artefacts relied on by transthoracic ultrasound have yet to be validated with TELU. Moreover, the relative invasiveness of TELU compared with transthoracic ultrasonography may limit its use to specific situations when the probe is already in place, as during cardiac anesthesia or when the anterior thorax is inaccessible. The main advantage of TELU may lie in the ability to integrate both cardiac and pulmonary assessments in one single examination. CONCLUSION: Anesthesiologists and intensivists who already use transesophageal echocardiography on a regular basis should consider adding TELU to their clinical assessment of hypoxemia and related pulmonary pathologies. Nevertheless, the literature specifically supporting TELU is relatively limited, and further validation studies are needed.

Clinical relevance of transcranial Doppler in a cardiac surgery setting: embolic load predicts difficult separation from cardiopulmonary bypass.

BACKGROUND: During cardiac surgery, transcranial Doppler (TCD) represents a non-invasive modality that allows measurement of red blood cell flow velocities in the cerebral arteries. TCD can also be used to detect and monitor embolic material in the cerebral circulation. Detection of microemboli is reported as a high intensity transient signal (HITS). The importance of cerebral microemboli during cardiac surgery has been linked to the increased incidence of postoperative renal failure, right ventricular dysfunction, and hemodynamic instability. The objective of this study is to determine whether the embolic load is associated with hemodynamic instability during cardiopulmonary bypass (CPB) separation and postoperative complications. METHODS: A retrospective single-centre cohort study of 354 patients undergoing cardiac surgery between December 2015 and March 2020 was conducted. Patients were divided in tertiles, where 117 patients had a low quantity of embolic material (LEM), 119 patients have a medium quantity of microemboli (MEM) and 118 patients who have a high quantity of embolic material (HEM). The primary endpoint was a difficult CPB separation. Multivariate logistic regression was used to determine the potential association between a difficult CPB separation and the number of embolic materials. RESULTS: Patients who had a difficult CPB separation had more HITS compared to patients who had a successful CPB separation (p < 0.001). In the multivariate analysis, patients with MEM decreased their odds of having a difficult CPB weaning compared to patients in the HEM group (OR = 0.253, CI 0.111-0.593; p = 0.001). In the postoperative period patients in the HEM group have a higher Time of Persistent Organ Dysfunction (TPOD), a longer stay in the ICU, a longer duration under vasopressor drugs and a higher mortality rate compared to those in the MEM and LEM groups. CONCLUSION: The result of this study suggests that a high quantity of cerebral embolic material increases the odds of having a difficult CPB separation. Also, it seems to be associated to more complex surgery, a longer CPB time, a higher TPOD and a longer stay in the ICU. Six out of eight patients who died in this cohort were in the HEM group.

Transesophageal Echocardiography in Patients in Cardiac Arrest: The Heart and Beyond.

Point of care ultrasound involves different ultrasound modalities and is useful to assist management in emergent clinical situations such as cardiac arrest. The use of point of care ultrasound in cardiac arrest has mainly been described using transthoracic echocardiography as a diagnostic and as a prognostic tool. However, cardiac evaluation using transthoracic echocardiography might be challenging because of patient-related or technical factors. Furthermore, its use during pulse check pauses has been associated with delays in chest compression resumption. Transesophageal echocardiography (TEE) overcomes these limitations by providing reliable and continuous imaging of the heart without interfering with cardiopulmonary resuscitation. In this narrative review we describe the role of TEE during cardiopulmonary resuscitation in 4 different applications: (1) chest compression quality feedback; (2) rhythm characterization; (3) diagnosis of reversible causes; and (4) procedural guidance. Considering its limitations, we propose an algorithm for the integration of TEE in patients with cardiac arrest with a focus on these 4 applications and extend its use to extracardiac applications.