Perioperative echocardiographic strain analysis: what anesthesiologists should know.

PURPOSE: Echocardiographic strain analysis by speckle tracking allows assessment of myocardial deformation during the cardiac cycle. Its clinical applications have significantly expanded over the last two decades as a sensitive marker of myocardial dysfunction with important diagnostic and prognostic values. Strain analysis has the potential to become a routine part of the perioperative echocardiographic examination for most anesthesiologist-echocardiographers but its exact role in the perioperative setting is still being defined. CLINICAL FEATURES: This clinical report reviews the principles underlying strain analysis and describes its main clinical uses pertinent to the field of anesthesiology and perioperative medicine. Strain for assessment of left and right ventricular function as well as atrial strain is described. We also discuss the potential role of strain to aid in perioperative risk stratification, surgical patient selection in cardiac surgery, and guidance of anesthetic monitor choice and clinical decision-making in the perioperative period. CONCLUSION: Echocardiographic strain analysis is a powerful tool that allows seeing what conventional 2D imaging sometimes fails to reveal. It often provides pathophysiologic insight into various cardiac diseases at an early stage. Strain analysis is readily feasible and reproducible thanks to the use of highly automated software platforms. This technique shows promising potential to become a valuable tool in the arsenal of the anesthesiologist-echocardiographer and aid in perioperative risk-stratification and clinical decision-making.

RéSUMé: OBJECTIF: L'analyse échocardiographique de la déformation cardiaque (strain analysis) par suivi des marqueurs acoustiques (speckle-tracking) permet d'évaluer la déformation du myocarde au cours du cycle cardiaque. Ses applications cliniques se sont considérablement développées au cours des deux dernières décennies en tant que marqueur sensible du dysfonctionnement myocardique, avec des valeurs diagnostiques et pronostiques importantes. L'analyse de la déformation cardiaque a le potentiel de devenir une partie intégrante de l'examen échocardiographique périopératoire de routine pour la plupart des anesthésiologistes-échocardiographes, mais son rôle exact dans le cadre périopératoire est encore en cours de définition. CARACTéRISTIQUES CLINIQUES: Ce rapport clinique passe en revue les principes qui sous-tendent l'analyse de la déformation cardiaque et décrit ses principales utilisations cliniques pertinentes dans le domaine de l'anesthésiologie et de la médecine périopératoire. L'analyse de la déformation cardique pour l'évaluation de la fonction ventriculaire gauche et droite ainsi que de la déformation auriculaire sont décrites. Nous discutons également du rôle potentiel de l'analyse de la déformation cardiaque pour aider à la stratification du risque périopératoire, à la sélection des patients en chirurgie cardiaque, à l'orientation du choix des moniteurs anesthésiques, et à la prise de décision clinique en période périopératoire. CONCLUSION: L'analyse échocardiographique de la déformation cardiaque est un outil puissant qui permet de voir ce que l'imagerie 2D conventionnelle ne parvient parfois pas à révéler. Elle fournit souvent un aperçu physiopathologique de diverses maladies cardiaques à un stade précoce. L'analyse de la déformation cardiaque est facilement réalisable et reproductible grâce à l'utilisation de plateformes logicielles hautement automatisées. Cette technique est potentiellement prometteuse et pourrait devenir un outil précieux dans l'arsenal de l'anesthésiologiste-échocardiographe et aider à la stratification du risque périopératoire et à la prise de décision clinique.

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.

A dimensional analysis of experienced intensive care unit nurses' clinical decision-making for bleeding after cardiac surgery.

BACKGROUND: Bleeding following cardiac surgery is common and serious, yet a gap persists in understanding how experienced intensive care nurses identify and respond to such complications. AIM: To describe the clinical decision-making of experienced intensive care unit nurses in addressing bleeding after cardiac surgery. STUDY DESIGN: This qualitative study adopted the Recognition-Primed Decision Model as its theoretical framework. Thirty-nine experienced nurses from four adult intensive care units participated in semi-structured interviews based on the critical decision method. The interviews explored their clinical judgements and decisions in bleeding situations, and data were analysed through dimensional analysis, an alternative to grounded theory. RESULTS: Participants maintained consistent vigilance towards post-cardiac surgery bleeding, recognizing it through a haemorrhagic dimension associated with blood loss and chest drainage and a hypovolemic dimension focusing on the repercussions of reduced blood volume. These dimensions organized their understanding of bleeding types (i.e., normal, medical, surgical, tamponade) and necessary actions. Their decision-making encompassed monitoring bleeding, identifying the cause, stopping the bleeding, stabilizing haemodynamic and supporting the patient and family. Participants also adapted their actions to specific circumstances, including local practices, professional autonomy, interprofessional dynamics and resource availability. CONCLUSIONS: Nurses' decision-making was shaped by their personal attributes, the patient's condition and contextual circumstances, underscoring their expertise and pivotal role in anticipating actions and adapting to diverse conditions. The concept of actionability emerged as the central dimension explaining their decision-making, defined as the capability to implement actions towards specific goals within the possibilities and constraints of a situation. RELEVANCE TO CLINICAL PRACTICE: This study underscores the need for continual updates to care protocols to align with current evidence and for quality improvement initiatives to close existing practice gaps. Exploring the concept of actionability further, developing adaptability-focused educational programmes, and understanding decision-making intricacies are crucial for informing nursing education and decision-support systems.

Pulmonary Vasodilator Response of Combined Inhaled Epoprostenol and Inhaled Milrinone in Cardiac Surgical Patients.

BACKGROUND: Pulmonary hypertension (PH) and right ventricular (RV) dysfunction are major complications in cardiac surgery. Intraoperative management of patients at high risk of RV failure should aim to reduce RV afterload and optimize RV filling pressures, while avoiding systemic hypotension, to facilitate weaning from cardiopulmonary bypass (CPB). Inhaled epoprostenol and inhaled milrinone (iE&iM) administered in combination before CPB may represent an effective strategy to facilitate separation from CPB and reduce requirements for intravenous inotropes during cardiac surgery. Our primary objective was to report the rate of positive pulmonary vasodilator response to iE&iM and, second, how it relates to perioperative outcomes in cardiac surgery. METHODS: This is a retrospective cohort study of consecutive patients with PH or RV dysfunction undergoing on-pump cardiac surgery at the Montreal Heart Institute from July 2013 to December 2018 (n = 128). iE&iM treatment was administered using an ultrasonic mesh nebulizer before the initiation of CPB. Demographic and baseline clinical data, as well as hemodynamic, intraoperative, and echocardiographic data, were collected using electronic records. An increase of 20% in the mean arterial pressure (MAP) to mean pulmonary artery pressure (MPAP) ratio was used to indicate a positive response to iE&iM. RESULTS: In this cohort, 77.3% of patients were responders to iE&iM treatment. Baseline systolic pulmonary artery pressure (SPAP) (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.24-2.16 per 5 mm Hg; P = .0006) was found to be a predictor of pulmonary vasodilator response, while a European System for Cardiac Operative Risk Evaluation (EuroSCORE II) score >6.5% was a predictor of nonresponse to treatment (≤6.5% vs >6.5% [reference]: OR, 5.19; 95% CI, 1.84-14.66; P = .002). Severity of PH was associated with a positive response to treatment, where a higher proportion of responders had MPAP values >30 mm Hg (42.4% responders vs 24.1% nonresponders; P = .0237) and SPAP values >55 mm Hg (17.2% vs 3.4%; P = .0037). Easier separation from CPB was also associated with response to iE&iM treatment (69.7% vs 58.6%; P = .0181). A higher proportion of nonresponders had a very difficult separation from CPB and required intravenous inotropic drug support compared to responders, for whom easy separation from CPB was more frequent. Use of intravenous inotropes after CPB was lower in responders to treatment (8.1% vs 27.6%; P = .0052). CONCLUSIONS: A positive pulmonary vasodilator response to treatment with a combination of iE&iM before initiation of CPB was observed in 77% of patients. Higher baseline SPAP was an independent predictor of pulmonary vasodilator response, while EuroSCORE II >6.5% was a predictor of nonresponse to treatment.

Assessment of fluid responsiveness in children using respiratory variations in descending aortic flow.

BACKGROUND: The primary aim of the current study was to investigate the ability of respiratory variations in descending aortic flow, measured with two-dimensional echo at the suprasternal notch (ΔVpeak dAo), to predict fluid responsiveness in anesthetized mechanically ventilated children. In addition, variations in peak descending aortic flow measured with apical transthoracic echo (ΔVpeak LVOT) were examined for the same properties. METHODS: Twenty-seven patients under general anesthesia were investigated in this prospective observational study. Cardiac output, ΔVpeak dAo, and ΔVpeak LVOT were measured at stable conditions after anesthesia induction. The measurements were repeated after a 10 mL kg-1 fluid bolus. Patients were classified as responders if stroke volume index increased by >15% after fluid bolus. The ability of each parameter to predict fluid responsiveness was assessed using receiver operating characteristic curves. RESULTS: Twenty-seven patients were analyzed, mean age and weight 43 months and 16 kg, respectively. Twelve responders and 15 non-responders were identified. ΔVpeak dAo was significantly higher in the responder group (14%, 95% confidence interval [CI]: 12%-17%) compared to the non-responder group (11%, 95% CI: 9%-13%) (p = .04) at baseline. Area under the ROC curve for ΔVpeak dAo and ΔVpeak LVOT was 0.73 (95% CI: 0.52-0.89, p = .02) and 0.56 (0.34-0.78, p = .3), respectively. A baseline level of ΔVpeak dAo of >14% predicted fluid responsiveness with a sensitivity of 58% (95% CI: 28%-85%) and specificity of 73% (95% CI: 45%-92%). CONCLUSION: In mechanically ventilated children, ΔVpeak dAo identified fluid responders with moderate diagnostic power in the current study. ΔVpeak LVOT failed to predict fluid responders in the current study.

Higher portal venous pulsatility is associated with worse clinical outcomes following congenital heart surgery: a single-centre prospective cohort study.

PURPOSE: Increased portal venous flow pulsatility is associated with major complications after adult cardiac surgery. Nevertheless, no data are available for pediatric patients with congenital heart disease. We hypothesized that Doppler parameters including portal flow pulsatility could be associated with postoperative outcomes in children undergoing various cardiac surgeries. METHODS: We conducted a prospective observational cohort study in children undergoing congenital cardiac surgery. We obtained postoperative portal, splenic, and hepatic venous Doppler data and perioperative clinical data including major postoperative complications. Portal and splenic venous flow pulsatility were calculated. We evaluated the association between venous Doppler parameters and adverse outcomes. The primary objective was to determine whether postoperative portal flow pulsatility could indicate major complications following congenital heart surgery. RESULTS: In this study, we enrolled 389 children, 74 of whom experienced major postoperative complications. The mean (standard deviation) portal pulsatility (44 [30]% vs 25 [14]%; 95% confidence interval [CI] for mean difference, 12 to 26; P < 0.001] and splenic pulsatility indices (41 [30]% vs 26 [16]%; 95% CI, 7 to 23; P < 0.001) were significantly higher in children with postoperative complications than in those without complications. The portal pulsatility index was able to help identify postoperative complications in biventricular patients and univentricular patients receiving bidirectional cavopulmonary shunt whereas it did not in other univentricular patients. An increased postoperative portal pulsatility index was significantly associated with major complications after pediatric cardiac surgery (odds ratio, 1.40; 95% CI, 1.29 to 1.91; P < 0.001). CONCLUSIONS: Higher portal venous pulsatility is associated with major postoperative complications in children undergoing cardiac surgery. Nevertheless, more data are needed to conclude the efficacy of portal venous pulsatility in patients with univentricular physiology. STUDY REGISTRATION: ClinicalTrials.gov (NCT03990779); registered 19 June 2019.

RéSUMé: OBJECTIF: L'augmentation de la pulsatilité du flux de la veine porte est associée à des complications majeures après une chirurgie cardiaque chez l'adulte. Néanmoins, aucune donnée n'est disponible pour la patientèle pédiatrique atteinte de cardiopathie congénitale. Nous avons émis l'hypothèse que les paramètres Doppler, y compris la pulsatilité du flux de la veine porte, pourraient être associés aux devenirs postopératoires des enfants bénéficiant de diverses chirurgies cardiaques. MéTHODE: Nous avons réalisé une étude de cohorte observationnelle prospective portant sur des enfants bénéficiant d'une chirurgie cardiaque congénitale. Nous avons obtenu des données Doppler des veines porte, spléniques et hépatiques postopératoires ainsi que des données cliniques périopératoires, y compris les complications postopératoires majeures. La pulsatilité du flux des veines porte et spléniques a été calculée. Nous avons évalué l'association entre les paramètres Doppler veineux et les issues indésirables. L'objectif principal était de déterminer si la pulsatilité du flux postopératoire de la veine porte pouvait constituer un indicateur des complications majeures après une chirurgie cardiaque congénitale. RéSULTATS: Dans cette étude, nous avons recruté 389 enfants, dont 74 ont présenté des complications postopératoires majeures. La pulsatilité moyenne de la veine porte (écart type) (44 [30] % vs 25 [14] %; intervalle de confiance [IC] à 95 % pour la différence moyenne, 12 à 26; P < 0,001] et les indices de pulsatilité splénique (41 [30] % vs 26 [16] %; IC 95 %, 7 à 23; P < 0,001) étaient significativement plus élevés chez les enfants présentant des complications postopératoires que chez les enfants sans complications. L'indice de pulsatilité de la veine porte a permis d'identifier les complications postopératoires chez les patient·es biventriculaires et les patient·es univentriculaires recevant une anastomose cavo-pulmonaire bidirectionnelle (procédure de Glenn), alors que ce n'était pas le cas chez les autres patient·es univentriculaires. Une augmentation postopératoire de l'indice de pulsatilité de la veine porte était significativement associée à des complications majeures après une chirurgie cardiaque pédiatrique (rapport de cotes, 1,40; IC 95 %, 1,29 à 1,91; P < 0,001). CONCLUSION: Une pulsatilité plus élevée de la veine porte est associée à des complications postopératoires majeures chez les enfants bénéficiant d'une chirurgie cardiaque. Néanmoins, davantage de données sont nécessaires pour conclure à l'efficacité de la pulsatilité de la veine porte chez les patient·es présentant une physiologie univentriculaire. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT03990779); enregistrée le 19 juin 2019.

Evaluation of Portal, Splenic, and Hepatic Vein Flows in Children Undergoing Congenital Heart Surgery.

OBJECTIVE: Little is known about changes in portal, splenic, and hepatic vein flow patterns in children undergoing congenital heart surgery. This study aimed to determine the characteristics of portal, splenic, and hepatic vein flow patterns using ultrasonography in children undergoing cardiac surgery. DESIGN: Single-center, prospective observational study. SETTING: Tertiary children's hospital, operating room. PARTICIPANTS: Children undergoing cardiac surgery. MEASUREMENT AND MAIN RESULTS: The authors obtained ultrasound data from the heart, inferior vena cava, portal, splenic, and hepatic veins before and after surgeries. In the biventricular group, which included children with atrial and ventricular septal defects and pulmonary stenosis (n = 246), the portal pulsatility index decreased from 38.7% to 25.6% (p < 0.001) after surgery. The preoperative portal pulsatility index was significantly higher in patients with pulmonary hypertension (43.3% v 27.4%; p < 0.001). In the single-ventricle group (n = 77), maximum portal vein flow velocities of Fontan patients were significantly lower (13.5 cm/s) compared with that of patients with modified Blalock-Taussig shunt (19.7 cm/s; p = 0.035) or bidirectional cavopulmonary shunt (23.1 cm/s; p < 0.001). The cardiac index was inversely correlated with the portal pulsatility index in the bidirectional cavopulmonary shunt and Fontan circulation. (ß = -5.693, r2 = 0.473; p = 0.001) The portal pulsatility index was correlated with splenic venous pulsatility and hepatic venous atrial reverse flow velocity in biventricular and single-ventricle groups. CONCLUSIONS: The characteristics of venous Doppler patterns in the portal, splenic, and hepatic veins differed according to congenital heart disease. Further studies are required to determine the association between splanchnic venous Doppler findings and clinical outcomes in this population.

Processed Electroencephalogram-Based Monitoring to Guide Sedation in Critically Ill Adult Patients: Recommendations from an International Expert Panel-Based Consensus.

BACKGROUND: The use of processed electroencephalography (pEEG) for depth of sedation (DOS) monitoring is increasing in anesthesia; however, how to use of this type of monitoring for critical care adult patients within the intensive care unit (ICU) remains unclear. METHODS: A multidisciplinary panel of international experts consisting of 21 clinicians involved in monitoring DOS in ICU patients was carefully selected on the basis of their expertise in neurocritical care and neuroanesthesiology. Panelists were assigned four domains (techniques for electroencephalography [EEG] monitoring, patient selection, use of the EEG monitors, competency, and training the principles of pEEG monitoring) from which a list of questions and statements was created to be addressed. A Delphi method based on iterative approach was used to produce the final statements. Statements were classified as highly appropriate or highly inappropriate (median rating ≥ 8), appropriate (median rating ≥ 7 but < 8), or uncertain (median rating < 7) and with a strong disagreement index (DI) (DI < 0.5) or weak DI (DI ≥ 0.5 but < 1) consensus. RESULTS: According to the statements evaluated by the panel, frontal pEEG (which includes a continuous colored density spectrogram) has been considered adequate to monitor the level of sedation (strong consensus), and it is recommended by the panel that all sedated patients (paralyzed or nonparalyzed) unfit for clinical evaluation would benefit from DOS monitoring (strong consensus) after a specific training program has been performed by the ICU staff. To cover the gap between knowledge/rational and routine application, some barriers must be broken, including lack of knowledge, validation for prolonged sedation, standardization between monitors based on different EEG analysis algorithms, and economic issues. CONCLUSIONS: Evidence on using DOS monitors in ICU is still scarce, and further research is required to better define the benefits of using pEEG. This consensus highlights that some critically ill patients may benefit from this type of neuromonitoring.

New developments in the understanding of right ventricular function in acute care.

PURPOSE OF REVIEW: Right ventricular dysfunction has an important impact on the perioperative course of cardiac surgery patients. Recent advances in the detection and monitoring of perioperative right ventricular dysfunction will be reviewed here. RECENT FINDINGS: The incidence of right ventricular dysfunction in cardiac surgery has been associated with unfavorable outcomes. New evidence supports the use of a pulmonary artery catheter in cardiogenic shock. The possibility to directly measure right ventricular pressure by transducing the pacing port has expanded its use to track changes in right ventricular function and to detect right ventricular outflow tract obstruction. The potential role of myocardial deformation imaging has been raised to detect patients at risk of postoperative complications. SUMMARY: Perioperative right ventricular function monitoring is based on echocardiographic and extra-cardiac flow evaluation. In addition to imaging modalities, hemodynamic evaluation using various types of pulmonary artery catheters can be achieved to track changes rapidly and quantitatively in right ventricular function perioperatively. These monitoring techniques can be applied during and after surgery to increase the detection rate of right ventricular dysfunction. All this to improve the treatment of patients presenting early signs of right ventricular dysfunction before systemic organ dysfunction ensue.

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.

Early Detection and Correction of Cerebral Desaturation With Noninvasive Oxy-Hemoglobin, Deoxy-Hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series.

Regional cerebral oxygen saturation (rS o2 ) obtained from near-infrared spectroscopy (NIRS) provides valuable information during cardiac surgery. The rS o2 is calculated from the proportion of oxygenated to total hemoglobin in the cerebral vasculature. Root O3 cerebral oximetry (Masimo) allows for individual identification of changes in total (ΔcHbi), oxygenated (Δ o2 Hbi), and deoxygenated (ΔHHbi) hemoglobin spectral absorptions. Variations in these parameters from baseline help identify the underlying mechanisms of cerebral desaturation. This case series represents the first preliminary description of Δ o2 Hbi, ΔHHbi, and ΔcHbi variations in 10 cardiac surgical settings. Hemoglobin spectral absorption changes can be classified according to 3 distinct variations of cerebral desaturation. Reduced cerebral oxygen content or increased cerebral metabolism without major blood flow changes is reflected by decreased Δ o2 Hbi, unchanged ΔcHbi, and increased ΔHHbi Reduced cerebral arterial blood flow is suggested by decreased Δ o2 Hbi and ΔcHbi, with variable ΔHHbi. Finally, acute cerebral congestion may be suspected with increased ΔHHbi and ΔcHbi with unchanged Δ o2 Hbi. Cerebral desaturation can also result from mixed mechanisms reflected by variable combination of those 3 patterns. Normal cerebral saturation can occur, where reduced cerebral oxygen content such as anemia is balanced by a reduction in cerebral oxygen consumption such as during hypothermia. A summative algorithm using rS o2 , Δ o2 Hbi, ΔHHbi, and ΔcHbi is proposed. Further explorations involving more patients should be performed to establish the potential role and limitations of monitoring hemoglobin spectral absorption signals.

Intra-abdominal pressure during and after cardiac surgery: a single-centre prospective cohort study.

PURPOSE: While intra-abdominal hypertension (IAH) has been associated with adverse outcomes in multiple settings, the epidemiology and clinical implications of IAH in the context of cardiac surgery are less known. In this study, we aimed to describe the prevalence of IAH in patients undergoing cardiac surgery and determine its association with patient characteristics and postoperative outcomes. METHODS: We conducted a single-centre prospective cohort study in which intra-abdominal pressure was measured in the operating room after general anesthesia (T1), after the surgical procedure (T2), and two hours after intensive care unit (ICU) admission (T3) in a subset of patients. Intra-abdominal hypertension was defined as intra-abdominal pressure (IAP) ≥ 12 mm Hg. Postoperative outcomes included death, acute kidney injury (AKI), and length of stay in the ICU and hospital. RESULTS: A total of 513 IAP measurements were obtained from 191 participants in the operating room and 131 participants in the ICU. Intra-abdominal hypertension was present in 105/191 (55%) at T1, 115/191 (60%) at T2, and 31/131 (24%) at T3. Intra-abdominal pressure was independently associated with body mass index, central venous pressure, and mean pulmonary artery pressure but was not associated with cumulative fluid balance. Intraoperative IAH was not associated with adverse outcomes including AKI. CONCLUSIONS: Intra-abdominal hypertension is very common during cardiac surgery but its clinical implications are uncertain.

RéSUMé: OBJECTIF: Bien que l'hypertension intra-abdominale (HIA) ait été associée à des issues indésirables dans de multiples contextes, l'épidémiologie et les implications cliniques de l'HIA dans le contexte de la chirurgie cardiaque sont moins connues. Dans cette étude, nous avons cherché à décrire la prévalence de l'HIA chez les patients bénéficiant d'une chirurgie cardiaque et à déterminer son association avec les caractéristiques des patients et les issues postopératoires. MéTHODE: Nous avons mené une étude de cohorte prospective monocentrique dans laquelle la pression intra-abdominale a été mesurée en salle d'opération après une anesthésie générale (T1), après l'intervention chirurgicale (T2) et deux heures après l'admission à l'unité de soins intensifs (USI) (T3) dans un sous-ensemble de patients. L'hypertension intra-abdominale a été définie comme une pression intra-abdominale (PIA) ≥ 12 mmHg. Les issues postopératoires comprenaient le décès, l'insuffisance rénale aiguë (IRA), et la durée du séjour à l'USI et à l'hôpital. RéSULTATS: Au total, 513 mesures de la PIA ont été obtenues auprès de 191 participants en salle d'opération et de 131 participants à l'USI. L'hypertension intra-abdominale était présente chez 105/191 patients (55 %) à T1, 115/191 (60 %) à T2 et 31/131 (24 %) à T3. La pression intra-abdominale était indépendamment associée à l'indice de masse corporelle, à la pression veineuse centrale et à la pression artérielle pulmonaire moyenne, mais n'était pas associée à un bilan hydrique cumulatif. L'HIA peropératoire n'était pas associée à des issues indésirables, y compris à l'IRA. CONCLUSION: L'hypertension intra-abdominale est très fréquente lors d'une chirurgie cardiaque, mais ses implications cliniques sont incertaines.

Constrictive pericarditis: portal, splenic, and femoral venous Doppler pulsatility: a case series.

PURPOSE: Pulsatile flow of the portal vein has been implicated as an indicator of right ventricular dysfunction in cardiac patients. In patients with significantly elevated right atrial pressure, pulsatile venous flow may be transmitted to the portal, splenic, renal, and femoral veins. We describe the evolution of these echocardiographic findings in four patients with constrictive pericarditis (CP) undergoing pericardiectomy with simultaneous hemodynamic waveform and cerebral oximetry monitoring in the operating room and in the intensive care unit. CLINICAL FEATURES: Patient 1 presented classic signs of CP, including equalization of left and right diastolic pressures, a "square root" sign on the diastolic portion of the right ventricular pressure curve, and elevated right atrial pressure. Preoperative transesophageal echocardiography showed a hyperdynamic left ventricle and dilated right ventricle with abnormal pulsatile waveforms in the portal and splenic veins. Surgical decompression of the pericardium gradually normalized the Doppler waveforms. Increased venous return following pericardiectomy during surgery in patients 2 and 3 and during the postoperative period in patient 4 resulted in right ventricular (RV) failure due to significantly increased preload. Venous pulsatility was also observed in the portal, splenic, and femoral veins. CONCLUSION: In patients with CP, changes in hemodynamic and echocardiographic signs of RV dysfunction are rapidly reflected by changes in peripheral venous velocities. Identifying signs of splanchnic and peripheral vascular venous congestion could help identify patients at higher risk of developing postoperative complications following pericardiectomy.

RéSUMé: OBJECTIF : Le flux pulsatile de la veine porte a été impliqué comme indicateur de dysfonctionnement ventriculaire droit chez les patients de chirurgie cardiaque. Le flux veineux pulsatile pourrait être transmis aux veines porte, splénique, rénale et fémorale chez les patients présentant une pression auriculaire droite significativement élevée. Nous décrivons l'évolution de ces observations échocardiographiques chez quatre patients atteints de péricardite constrictive (PC) bénéficiant d'une péricardectomie avec monitorage simultané de la forme d'onde hémodynamique et de l'oxymétrie cérébrale en salle d'opération et à l'unité de soins intensifs. CARACTéRISTIQUES CLINIQUES: Le patient 1 présentait des signes classiques de PC, y compris l'égalisation des pressions diastoliques gauche et droite, un signe de « racine carrée ¼ sur la partie diastolique de la courbe de pression ventriculaire droite, et une pression auriculaire droite élevée. L'échocardiographie transœsophagienne préopératoire a montré un ventricule gauche hyperdynamique et un ventricule droit dilaté, avec des formes d'onde pulsatiles anormales dans les veines porte et splénique. La décompression chirurgicale du péricarde a progressivement normalisé les formes d'onde Doppler. L'augmentation du retour veineux suivant une péricardectomie, survenue pendant la chirurgie chez les patients 2 et 3 et en période postopératoire chez le patient 4, a entraîné une défaillance ventriculaire droite (VD) due à l'augmentation significative de la précharge. La pulsatilité veineuse a également été observée dans les veines porte, splénique et fémorale. CONCLUSION: Chez les patients atteints de péricardite constrictive, les changements dans les signes hémodynamiques et échocardiographiques de dysfonctionnement du VD sont rapidement reflétés par des changements dans la vélocité veineuse périphérique. L'identification des signes de congestion veineuse splanchnique et vasculaire périphérique pourrait aider à identifier les patients présentant un risque plus élevé de manifester des complications postopératoires après une péricardectomie.

Impact of Processed Electroencephalography in Cardiac Surgery: A Retrospective Analysis.

OBJECTIVE: The use of brain function monitoring with processed electroencephalography (pEEG) during cardiac surgery is gaining interest for the optimization of hypnotic agent delivery during the maintenance of anesthesia. The authors sought to determine whether the routine use of pEEG-guided anesthesia is associated with a reduction of hemodynamic instability during cardiopulmonary bypass (CPB) separation and subsequently reduces vasoactive and inotropic requirements in the intensive care unit. DESIGN: This is a retrospective cohort study based on an existing database. SETTING: A single cardiac surgical center. PARTICIPANTS: Three hundred patients undergoing cardiac surgery, under CPB, between December 2013 and March 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred and fifty patients had pEEG-guided anesthesia, and 150 patients did not have a pEEG-guided anesthesia. Multiple logistic regression demonstrated that pEEG-guided anesthesia was not associated with a successful CPB separation (p = 0.12). However, the use of pEEG-guided anesthesia reduced by 57% the odds of being in a higher category for vasoactive inotropic score compared to patients without pEEG (odds ratio = 0.43; 95% confidence interval: 0.26-0.73; p = 0.002). Duration of mechanical ventilation, fluid balance, and blood losses were also reduced in the pEEG anesthesia-guided group (p < 0.003), but there were no differences in organ dysfunction duration and mortality. CONCLUSION: During cardiac surgery, pEEG-guided anesthesia allowed a reduction in the use of inotropic or vasoactive agents at arrival in the intensive care unit. However, it did not facilitate weaning from CPB compared to a group where pEEG was unavailable. A pEEG-guided anesthetic management could promote early vasopressor weaning after cardiac surgery.

Subsyndromal Delirium in Cardiac Surgery Patients: Risk Factors and Outcomes of the Different Trajectories.

BACKGROUND: Subsyndromal delirium (SSD), a subthreshold form of delirium, is related to longer length of stay and increased mortality rates among older adults. Risk factors and outcomes of SSD in cardiac surgery patients are not fully understood. OBJECTIVE: The aim of this study was to assess and describe the characteristics and outcomes related to trajectories of SSD and delirium in cardiac surgery patients. METHODS: In this secondary analysis of a retrospective case-control (1:1) cohort study, SSD was defined as a score between 1 and 3 on the Intensive Care Delirium Screening Checklist paired with an absence of diagnosis of delirium on the day of assessment. Potential risk factors (eg, age) and outcomes (eg, mortality) were identified from existing literature. Patients were grouped into 4 trajectories: (1) without SSD or delirium, (2) SSD only, (3) both, and (4) delirium only. These trajectories were contrasted using analysis of variance or χ2 test. RESULTS: Among the cohort of 346 patients, 110 patients did not present with SSD or delirium, 62 presented with only SSD, 69 presented with both, and 105 presented with only delirium. In comparison with patients without SSD or delirium, patients with SSD presented preoperative risk factors known for delirium (ie, older age, higher European System for Cardiac Operative Risk Evaluation II) but underwent less complicated surgical procedures, received fewer transfusions postoperatively, and had a lower positive fluid balance postoperatively than patients who presented with delirium. Patients with both SSD and delirium had worse outcomes in comparison with those with delirium only. CONCLUSION: This study stresses the importance for healthcare professionals to identify SSD and prevent its progression to delirium.

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.

Ultrasound evaluation of inferior vena cava compression in tilted and supine term parturients.

PURPOSE: Hypotension is common following spinal anesthesia (SA) during elective Cesarean delivery (CD). Although common practice is to alleviate inferior vena cava (IVC) compression, limited evidence supports a 15° tilt for CD. We measured collapsibility of the IVC in supine and 15° left lateral tilt positions with ultrasound before and after SA and phenylephrine infusion in term parturients. METHODS: Twenty term parturients scheduled for CD were recruited for this prospective study. Ultrasound measurements of the IVC were taken 1) supine before SA, 2) tilted 15° before SA, 3) supine after SA, and 4) tilted 15° after SA. A phenylephrine infusion was begun after injection of SA. The primary outcome was to evaluate the impact of position on the IVC collapsibility index (IVCCI): a measure of the difference between the maximum and minimum IVC diameter with respiration. RESULTS: The mean (standard deviation) IVCCI (%) before SA was higher in the supine 19.5 (8.0) than in the tilted 15.0 (6.4) position (mean difference, 4.5; 95% confidence interval [CI], 0.1 to 8.9; P = 0.04). After SA, there was no significant difference between IVCCI (%) in the supine 17.8 (8.3) and tilted 14.2 (6.9) position (mean difference, 3.5; 95% CI, -0.9 to 7.9; P = 0.13). There was no correlation between the pre-spinal IVVCI measurements and the quantity of phenylephrine used during the surgery. CONCLUSION: The IVCCI was lower in the 15° tilt position than in the supine position, but not after SA with a phenylephrine infusion. Ultrasound imaging can help identify IVC compression. TRIAL REGISTRATION: www.clinicaltrials.gov (NCT03410199); registered 18 January 2018.

RéSUMé: OBJECTIF: L'hypotension est fréquente après une rachianesthésie pendant un accouchement par césarienne programmée (CP). Bien que la pratique courante consiste à atténuer la compression de la veine cave inférieure (VCI), des données probantes limitées encouragent une latéralisation de 15 ° durant la CP. Avec l'échographie, nous avons mesuré la collapsibilité de la VCI en décubitus dorsal et en position d'inclinaison latérale gauche de 15° avant et après la rachianesthésie et la perfusion de phényléphrine chez des parturientes à terme. MéTHODE: Vingt parturientes à terme devant subir une CP ont été recrutées dans le cadre de cette étude prospective. Les mesures échographiques de la VCI ont été prises 1) en décubitus dorsal avant la rachianesthésie, 2) avec une latéralisation de 15° avant la rachianesthésie, 3) en décubitus dorsal après la rachianesthésie, et 4) avec une latéralisation de 15° après la rachianesthésie. Une perfusion de phényléphrine a été amorcée après l'injection de la rachianesthésie. Le critère d'évaluation principal était l'impact de la position sur l'indice de collapsibilité de la VCI (ICVCI), soit une mesure de la différence entre les diamètres maximal et minimal de la VCI avec respiration. RéSULTATS: Le ICVCI moyen (écart type) (%) avant la rachianesthésie était plus élevé en décubitus dorsal, à 19,5 (8,0), qu'en position latéralisée, à 15,0 (6,4) (différence moyenne, 4,5; intervalle de confiance [IC] 95 %, 0,1 à 8,9; P = 0,04). Après la rachianesthésie, aucune différence significative n'a été observée entre l'ICVCI (%) en décubitus dorsal, à 17,8 (8,3), et en position latéralisée, à 14,2 (6,9) (différence moyenne, 3,5; IC 95 %, -0,9 à 7,9; P = 0,13). Il n'y avait aucune corrélation entre les mesures de l'ICVCI pré-rachianesthésie et la quantité de phényléphrine utilisée pendant la chirurgie. CONCLUSION: L'ICVCI était plus bas en position latéralisée à 15 ° qu'en décubitus dorsal, mais pas après une rachianesthésie avec une perfusion de phényléphrine. L'échographie peut aider à identifier la compression de la VCI. ENREGISTREMENT DE L'éTUDE: www.clinicaltrials.gov (NCT03410199); enregistrée le 18 janvier 2018.

A proposed algorithm for combining transcranial Doppler ultrasound monitoring with cerebral and somatic oximetry: a case report.

PURPOSE: Transcranial Doppler (TCD) ultrasound is a non-invasive monitor of cerebral blood velocity that can be used intraoperatively. The purpose of this report is to describe how different patterns seen on TCD can help identify the cause of cerebral desaturation when near-infrared spectroscopy (NIRS) oximetry is used concomitantly. CLINICAL FEATURES: A 69-yr-old male patient undergoing coronary revascularisation and aortic valve replacement developed perioperative complications that were detected using a combination of transtemporal TCD of the middle cerebral artery along with cerebral and somatic NIRS. Initial brain desaturation was secondary to hypocapnia during which TCD-derived blood velocity and somatic NIRS values remained unchanged. After the procedure, a second episode of brain desaturation occurred secondary to a technical issue with the aortic valve prosthesis requiring a return to cardiopulmonary bypass (CPB); there were no high-intensity transient signals (HITS) on TCD. Brain desaturation occurred a third time following the second attempt to separate from CPB at which time TCD detected a significant amount of HITS suggesting air emboli that were associated with acute right ventricular dysfunction; there was also a reduction in somatic NIRS. CONCLUSIONS: Combining TCD with cerebral NIRS allows for the rapid identification of three different mechanisms of brain desaturation. An algorithm is proposed to help identify the origin of NIRS cerebral desaturation. Prospective clinical trials are needed to investigate potential benefits of multimodal brain monitoring and its impact on short and/or long-term clinical outcomes.

RéSUMé: OBJECTIF: L'échographie par Doppler transcrânien (DTC) est un moniteur non invasif de la vélocité sanguine cérébrale qui peut être utilisé en période peropératoire. L'objectif de ce compte rendu est de décrire comment différents tracés observés sur le DTC peuvent aider l'anesthésiologiste à identifier la cause de la désaturation cérébrale lorsque l'oxymétrie par spectroscopie proche infrarouge (SPIR) est utilisée de manière concomitante. ÉLéMENTS CLINIQUES: Un homme de 69 ans subissant une revascularisation coronarienne et un remplacement de valve aortique a présenté des complications périopératoires détectées grâce à la combinaison d'un DTC trans-temporal de l'artère cérébrale moyenne et d'une SPIR cérébrale et somatique. La désaturation cérébrale initiale était secondaire à une hypocapnie, pendant laquelle la vélocité sanguine dérivée du DTC et les valeurs de SPIR somatique sont demeurées inchangées. Après l'intervention, un deuxième épisode de désaturation cérébrale est survenu suite à un problème technique avec la prothèse de valve aortique, nécessitant un retour sous circulation extracorporelle (CEC); il n'y avait pas de signaux transitoires de haute intensité (HITS) sur le DTC. Il y a eu un troisième épisode de désaturation cérébrale suite à la deuxième tentative de sevrage de la CEC; à ce moment-là, le DTC a détecté une quantité significative de HITS, suggérant des embolies gazeuses associées à une insuffisance ventriculaire droite aiguë; une réduction de la SPIR somatique a également été observée. CONCLUSION: La combinaison du DTC à la SPIR cérébrale a permis d'identifier trois différents mécanismes de désaturation cérébrale. Un algorithme est proposé pour aider le clinicien à déterminer l'origine de la désaturation cérébrale sur la SPIR. Des études cliniques prospectives sont nécessaires afin d'explorer les avantages potentiels d'un monitorage cérébral multimodal et son impact sur les devenirs cliniques à court et à long terme.

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.

Clinical and Technical Limitations of Cerebral and Somatic Near-Infrared Spectroscopy as an Oxygenation Monitor.

Cerebral and somatic near-infrared spectroscopy monitors are commonly used to detect tissue oxygenation in various circumstances. This form of monitoring is based on tissue infrared absorption and can be influenced by several physiological and non-physiological factors that can induce error in the interpretation. This narrative review explores those clinical and technical limitations and proposes solutions and alternatives in order to avoid some of those pitfalls.