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.

Association of Initial Pulseless Electrical Activity Heart Rate and Clinical Outcomes following Adult Non-Traumatic Out-of-Hospital Cardiac Arrest.

OBJECTIVE: Studies evaluating the prognostic value of the pulseless electrical activity (PEA) heart rate in out-of-hospital cardiac arrest (OHCA) patients have reported conflicting results. The objective of this study was to evaluate the association between the initial PEA heart rate and favorable clinical outcomes for OHCA patients. METHODS: The present post-hoc cohort study used the Resuscitation Outcomes Consortium Cardiac Epidemiologic Registry Version 3, which included OHCA patients in seven US and three Canadian sites from April 2011 to June 2015. The primary outcome was survival to hospital discharge and the secondary outcome was survival with a good functional outcome. For the primary analysis, the patients were separated into eight groups according to their first rhythms and PEA heart rates: (1) initial PEA heart rate of 1-20 beats per minute (bpm); (2) 21-40 bpm; (3) 41-60 bpm; (4) 61-80 bpm; (5) 81-100 bpm; (6) 101-120 bpm; (7) over 120 bpm; (8) initial shockable rhythm (reference category). Multivariable logistic regression models were used to assess the associations of interest. RESULTS: We identified 17,675 patients (PEA: 7,089 [40.1%]; initial shockable rhythm: 10,797 [59.9%]). Patients with initial PEA electrical frequencies ≤100 bpm were less likely to survive to hospital discharge than patients with initial shockable rhythms (1-20 bpm: adjusted odds ratio [AOR] = 0.15 [95%CI 0.11-0.21]; 21-40 bpm: AOR = 0.21 [0.18-0.25]; 41-60 bpm: AOR = 0.30 [0.25-0.36]; 61-80 bpm: AOR = 0.37 [0.28-0.49]; 81-100 bpm: AOR = 0.55 [0.41-0.65]). However, there were no statistical outcome differences between PEA patients with initial electrical frequencies of >100 bpm and patients with initial shockable rhythms (101-120 bpm: AOR = 0.65 [95%CI 0.42-1.01]; >120 bpm: AOR = 0.72 [95%CI 0.37-1.39]). Similar results were observed for survival with good functional outcomes (101-120 bpm: AOR = 0.60 [95%CI 0.31-1.15]; >120 bpm: AOR = 1.08 [95%CI 0.50-2.28]). CONCLUSIONS: We observed a good association between higher initial PEA electrical frequency and favorable clinical outcomes for OHCA patients. As there is no significant difference in outcomes between patients with initial PEA heart rates of more than 100 bpm and those with initial shockable rhythms, we can hypothesize that these patients could be considered in the same prognostic category.

Accuracy of the Initial Rhythm to Predict a Short No-Flow Time in Out-of-Hospital Cardiac Arrest.

OBJECTIVES: The no-flow time (NFT) can help establish prognosis in out-of-hospital cardiac arrest (OHCA) patients. It is often used as a selection criterion for extracorporeal resuscitation. In patients with an unwitnessed OHCA for whom the NFT is unknown, the initial rhythm has been proposed to identify those more likely to have had a short NFT. Our objective was to determine the predictive accuracy of an initial shockable rhythm for an NFT of 5 minutes or less (NFT ≤ 5). DESIGN: Retrospective analysis of prospectively collected data. SETTING: Prehospital OHCA in eight U.S. and three Canadian sites. PATIENTS: A total of 28,139 adult patients with a witnessed nontraumatic OHCA were included, of whom 11,228 (39.9%) experienced an emergency medical service-witnessed OHCA (NFT = 0), 695 (2.7%) had a bystander-witnessed OHCA, and an NFT less than or equal to 5, and 16,216 (57.6%) with a bystander-witnessed OHCA and an NFT greater than 5. INTERVENTIONS: Sensitivity, specificity, and likelihood ratios of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 minutes. MEASUREMENTS AND MAIN RESULTS: The sensitivity of an initial shockable rhythm to identify patients with an NFT less than or equal to 5 was poor (25% [95% CI, 25-26]), but specificity was moderate (70% [95% CI, 69-71]). The positive and likelihood ratios were inverted (negative accuracy) (positive likelihood ratio, 0.76 [95% CI, 0.74-0.79]; negative likelihood ratio, 1.12 [95% CI, 1.10-1.12]). Including only patients with a bystander-witnessed OHCA improved the sensitivity to 48% (95% CI, 45-52), the positive likelihood ratio to 1.45 (95% CI, 1.33-1.58), and the negative likelihood ratio to 0.77 (95% CI, 0.72-0.83), while slightly lowering the specificity to 67% (95% CI, 66-67). CONCLUSIONS: Our analysis demonstrated that the presence of a shockable rhythm at the time of initial assessment was poorly sensitive and only moderately specific for OHCA patients with a short NFT. The initial rhythm, therefore, should not be used as a surrogate for NFT in clinical decision-making.

Parameters associated with successful weaning of veno-arterial extracorporeal membrane oxygenation: a systematic review.

PURPOSE: Veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) can be used to restore organ perfusion in patients with cardiogenic shock until native heart recovery occurs. It may be challenging, however, to determine when patients can be weaned successfully from ECMO-surviving without requiring further mechanical support or heart transplant. We aimed to systematically review the medical literature to determine the biomarkers, hemodynamic and echocardiographic parameters associated with successful weaning of VA-ECMO in adults with cardiogenic shock and to present an evidence-based weaning algorithm incorporating key findings. METHOD: We systematically searched PubMed, Embase, ProQuest, Google Scholars, Web of Science and the Grey literature for pertinent original research reports. We excluded studies limited to extracorporeal cardiopulmonary resuscitation (ECPR) as the neurological prognosis may significantly alter the decision-making process surrounding the device removal in this patient population. Studies with a mixed population of VA-ECMO for cardiogenic shock or cardiac arrest were included. We excluded studies limited to patients in which ECMO was only used as a bridge to VAD or heart transplant, as such patients are, by definition, never "successfully weaned." We used the Risk of Bias Assessment tool for Non-Randomized Studies. The study was registered on the International prospective register of systematic reviews (PROSPERO CRD42020178641). RESULTS: We screened 14,578 records and included 47 that met our pre-specified criteria. Signs of lower initial severity of shock and myocardial injury, early recovery of systemic perfusion, left and right ventricular recovery, hemodynamic and echocardiographic stability during flow reduction trial and/or pump-controlled retrograde trial off predicted successful weaning. The most widely used parameter was the left ventricular outflow tract velocity time integral, an indicator of stroke volume. Most studies had a moderate or high risk of bias. Heterogeneity in methods, timing, and conditions of measurements precluded any meta-analysis. CONCLUSIONS: In adult patients on VA-ECMO for cardiogenic shock, multiple biomarkers, hemodynamic and echocardiographic parameters may be used to track resolution of systemic hypoperfusion and myocardial recovery in order to identify patients that can be successfully weaned.

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.

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.

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.

Early experience with critically ill patients with COVID-19 in Montreal.

PURPOSE: Montreal has been the epicentre of the coronavirus disease (COVID-19) pandemic in Canada. Given the regional disparities in incidence and mortality in the general population, we aimed to describe local characteristics, treatments, and outcomes of critically ill COVID-19 patients in Montreal. METHODS: A single-centre retrospective cohort of consecutive adult patients admitted to the intensive care unit (ICU) of Hôpital du Sacré-Coeur de Montréal with confirmed COVID-19 were included. RESULTS: Between 20 March and 13 May 2020, 75 patients were admitted, with a median [interquartile range (IQR)] age of 62 [53-72] yr and high rates of obesity (47%), hypertension (67%), and diabetes (37%). Healthcare-related infections were responsible for 35% of cases. The median [IQR] day 1 sequential organ failure assessment score was 6 [3-7]. Invasive mechanical ventilation (IMV) was used in 57% of patients for a median [IQR] of 11 [5-22] days. Patients receiving IMV were characterized by a moderately decreased median [IQR] partial pressure of oxygen:fraction of inspired oxygen (day 1 PaO2:FiO2 = 177 [138-276]; day 10 = 173 [147-227]) and compliance (day 1 = 48 [38-58] mL/cmH2O; day 10 = 34 [28-42] mL/cmH2O) and very elevated estimated dead space fraction (day 1 = 0.60 [0.53-0.67]; day 10 = 0.72 [0.69-0.79]). Overall hospital mortality was 25%, and 21% in the IMV patients. Mortality was 82% in patients ≥ 80 yr old. CONCLUSIONS: Characteristics and outcomes of critically ill patients with COVID-19 in Montreal were similar to those reported in the existing literature. We found an increased physiologic dead space, supporting the hypothesis that pulmonary vascular injury may be central to COVID-19-induced lung damage.

RéSUMé: OBJECTIF: Montréal a été l'épicentre de la pandémie du coronavirus (COVID-19) au Canada. Étant donné les disparités régionales dans l'incidence et la mortalité dans la population générale, nous avons tenté de décrire les caractéristiques locales, les traitements et le devenir des patients atteints de la COVID-19 en état critique à Montréal. MéTHODE: Notre étude de cohorte rétrospective monocentrique a inclus tous les patients adultes admis consécutivement à l'unité de soins intensifs de l'Hôpital du Sacré-Cœur de Montréal avec un diagnostic confirmé de COVID-19. RéSULTATS: Soixante-quinze patients ont été admis entre le 20 mars et le 13 mai 2020. Ceux-ci avaient un âge médian [écart interquartile (ÉIQ)] de 62 [53­72] ans et présentaient une incidence élevée d'obésité (47 %), d'hypertension (67 %) et de diabète (37 %). Les transmissions associées aux soins de santé étaient responsables de 35 % des cas. Au jour 1, le score SOFA (Sequential Organ Failure Assessment ­ évaluation séquentielle de défaillance des organes) médian [ÉIQ] était de 6 [3­7]. La ventilation mécanique invasive (VMI) a été utilisée chez 57 % des patients, pour une durée médiane [ÉIQ] de 11 [5­22] jours. Les patients ayant reçu une VMI étaient caractérisés par une médiane [ÉIQ] modérément réduite de la pression partielle de la fraction d'oxygène inspiré (jour 1 PaO2:FiO2 = 177 [138­276]; jour 10 = 173 [147­227]), de la compliance (jour 1 = 48 [38­58] mL/cmH2O; jour 10 = 34 [28­42] mL/cmH2O), ainsi que par une fraction d'espace mort estimé très élevée (jour 1 = 0,60 [0,53-0,67]; jour 10 = 0,72 [0,69-0,79]). La mortalité hospitalière était de 25 % globalement, et de 21 % chez les patients avec VMI. La mortalité a atteint 82 % chez les patients agés de ≥ 80 ans. CONCLUSION: Les caractéristiques et le devenir des patients en état critique atteints de la COVID-19 à Montréal étaient semblables à ceux rapportés dans la littérature existante. Nous avons observé un espace mort physiologique augmenté, ce qui appuie l'hypothèse que des lésions vasculaires pulmonaires seraient primordiales dans les lésions pulmonaires induites par la COVID-19.

Early and Long-Term Outcomes after Direct Bridge-to-Transplantation with Extracorporeal Membrane Oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as direct bridge-to-transplantation (dBTT) remains controversial. We compared the short- and long-term outcomes of adult patients undergoing urgent heart transplantation (HT) with (dBTT) and without (non-BTT) VA-ECMO support at the time of HT. METHODS: Adults who underwent urgent HT in two institutions were assessed (N = 133; dBTT: N = 34 and non-BTT: N = 99). Patient characteristics, donor characteristics, in-hospital outcomes, and overall survival were compared. Mean follow up was 77±38 months and was 100% complete. Mortality predictors were identified using univariate and multivariate analyses. RESULTS: Before HT, patients with dBTT had higher rates of ischemic cardiomyopathy, acute kidney injury, liver failure, respiratory failure, and longer graft ischemia times. More patients in the dBTT group had complications, such as requiring VA-ECMO postoperatively (dBTT=50% vs. non-BTT=20%, P < 0.01). Hospital deaths (dBTT=23% vs. non-BTT=19%, P = 0.58), one-year (74% vs. 80%) and five-year survival (62% vs. 75%, P = 0.74 for overall survival) were not significantly different. The MELD-XI score and previous cardiac surgery were independent predictors of hospital mortality. CONCLUSION: Direct bridge-to-transplantation in patients on VA-ECMO support was not associated with worse long-term outcomes compared with non-VA-ECMO urgent HT, especially in recipients without any associated organ failure and a low MELD-XI score before HT.

Use of extracorporeal membrane oxygenation for heart graft dysfunction in adults: incidence, risk factors and outcomes in a multicentric study.

BACKGROUND: The decision about whether to use venoarterial extracorporeal membrane oxygenation (VA-ECMO) in patients with cardiac graft dysfunction (GD) is usually made on a case-by-case basis and is guided by the team's experience. We aimed to determine the incidence of VA-ECMO use after heart transplantation (HT), to assess early- and long-term outcomes and to assess risk factors for the need for VA-ECMO and early mortality in these patients. METHODS: We included adults who underwent heart transplantation at 3 cardiac centres who met the most recent International Society for Heart and Lung Transplantation definition of graft dysfunction (GD) over a 10-year period. Pre-transplant, intraoperative and posttransplant characteristics of the heart recipients as well as donor characteristics were analyzed and compared among recipients with GD treated with and without VA-ECMO. RESULTS: There were 135 patients with GD in this study, of whom 66 were treated with VA-ECMO and 69 were not. The mean follow-up averaged 81.2 months (standard deviation 36 mo, range 0-184 mo); follow-up was complete in 100% of patients. The overall incidence of GD (30%) and of VA-ECMO use increased over the study period. We did not identify any predictive pre-transplantation factors for VA-ECMO use, but patients who required VA-ECMO had higher serum lactate levels and higher inotropes doses after HT. The overall survival rates were 83% and 42% at 1 year and 78% and 40% at 5 years among patients who received only medical treatment and those who received VA-ECMO, respectively. Delayed initiation of VA-ECMO and postoperative bleeding were strongly associated with increased in-hospital mortality. CONCLUSION: The incidence of GD increased over the study period, and the need for VA-ECMO among patients with GD remains difficult to predict. In-hospital mortality decreased over time but remained high among patients who required VA-ECMO, especially among patients with delayed initiation of VA-ECMO.

Venoarterial Extracorporeal Membrane Oxygenation Support for Severe Pericardial Decompression Syndrome: A Case Report.

OBJECTIVES: We report a case of a man with tamponade decompression syndrome following pericardial drainage. DATA SOURCES: ICU - Montreal Heart Institute. STUDY SELECTION: Case report. DATA EXTRACTION: Clinical and surgical records. DATA SYNTHESIS: None. CONCLUSIONS: Our case adds further concerns in supporting a patient with tamponade decompression syndrome, including mechanical circulatory support, due to the reversible nature of this condition.

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.

Preoperative Diaphragm Function Is Associated With Postoperative Pulmonary Complications After Cardiac Surgery.

OBJECTIVES: Postoperative pulmonary complications increase mortality, length, and cost of hospitalization. A better diaphragmatic strength may help face an increased work of breathing postoperatively. We, therefore, sought to determine if a low preoperative diaphragm thickening fraction (TFdi) determined by ultrasonography helped predict the occurrence of postoperative pulmonary complications after cardiac surgery independently of indicators of frailty, sarcopenia, and pulmonary function. DESIGN: Prospective observational cohort study. SETTING: Montreal Heart Institute, an academic cardiac surgery center in Canada. PATIENTS: Adults undergoing nonemergency cardiac surgery. INTERVENTIONS: We measured the preoperative thickness of the right and left hemidiaphragms at their zone of apposition at end-expiration (Tdi,ee) and peak-inspiration (Tdi,ei) with ultrasonography. Maximal thickening fraction of the diaphragm during inspiration (TFdi,max) was calculated using the following formula: TFdi,max = (Tdi,ei-Tdi,ee)/Tdi,ee. We also evaluated other potential risk factors including demographic parameters, comorbidities, Clinical Frailty Scale, grip strength, 5-meter walk test, and pulmonary function tests. We repeated TFdi,max measurements within 24 hours of extubation. The primary composite outcome of this study was the occurrence of postoperative pulmonary complications, defined as pneumonia, clinically significant atelectasis, or prolonged mechanical ventilation (> 24 hr). MEASUREMENT AND MAIN RESULTS: Of the 115 patients included, 34 (29.6%) developed postoperative pulmonary complications, including two with pneumonia, four with prolonged mechanical ventilation, and 32 with clinically significant atelectasis. Those with postoperative pulmonary complications had prolonged ICU and hospital length of stays. They had a lower TFdi,max (37% [interquartile range, 31-45%] vs 44% [interquartile range, 33-58%]; p = 0.03). In multiple logistic regression, a TFdi,max less than 38.1% was associated with postoperative pulmonary complications (odds ratio, 4.9; 95% CI, 1.81-13.50; p = 0.002). All patients who developed pneumonia or prolonged mechanical ventilation had a TFdi,max less than 38.1%. Respiratory rate and diabetes were also independently associated with postoperative pulmonary complications, while pulmonary function tests and the assessed indicators of frailty and sarcopenia were not. CONCLUSIONS: A low preoperative TFdi,max can help to identify patients at increased risk of postoperative pulmonary complications after cardiac surgery.

Noninvasive Administration of Inhaled Nitric Oxide and its Hemodynamic Effects in Patients With Acute Right Ventricular Dysfunction.

OBJECTIVE: The authors aimed to assess the hemodynamic effects and demonstrate the feasibility of inhaled nitric oxide (iNO) in hemodynamically unstable patients with acute right ventricular (RV) dysfunction and to explore the safety profile of this approach. DESIGN: Retrospective cohort study. SETTING: Intensive care unit (ICU) of 2 tertiary care centers between January 2013 and 2017. PARTICIPANTS: All patients with RV dysfunction in whom iNO was initiated without invasive mechanical ventilation. INTERVENTION: Noninvasive administration of iNO. MEASUREMENTS AND MAIN RESULTS: Eighteen patients received the intervention during the study period; 8 of these patients had a pulmonary artery catheter and 2 had a pulse contour analysis device. Median (interquartile range) iNO concentration was 20 (20-20) ppm, and therapy duration was 24 (12-46) hours. Most patients received iNO through nasal prongs (66.7%) or a high-flow nasal cannula (27.8%). Within 1 hour, iNO reduced pulmonary vascular resistance from 219.1 to 165.4 dyn•s/cm5 (n = 7; p < 0.001), mean pulmonary artery pressure from 28.4 to 25.3 mmHg (n = 8; p = 0.01), and central venous pressure from 17.5 to 13.1 mmHg (n = 16; p = 0.001). Indexed cardiac output increased from 2.0 to 2.6 L/min/m2 (n = 9; p = 0.004). ICU mortality was 27.78%, and median ICU length of stay was 7 (5-9) days. Two significant bleeding episodes requiring intervention and 1 acute kidney injury occurred during iNO therapy. No headache was reported. CONCLUSION: Noninvasively administered iNO was associated with favorable hemodynamic effects in ICU patients with acute RV dysfunction. These results suggest the safety and feasibility of this therapy for which further prospective study is warranted.

A Practical Approach to Cerebro-Somatic Near-Infrared Spectroscopy and Whole-Body Ultrasound.

Near-infrared spectroscopy (NIRS) is an emerging noninvasive monitoring modality based on chromophore absorption of infrared light. Because NIRS provides instantaneous information on cerebral and somatic tissue oxygenation, it becomes mandatory to identify rapidly the etiology of impaired regional oxygenation and thus perfusion. To do so, the use of whole-body ultrasound (WHOBUS) represents a significant advance in the management of patients experiencing cerebral or somatic desaturation. This narrative review describes the authors' experience since 2002 in the use of combined NIRS and WHOBUS. A practical approach in the use of both modalities and their respective limitations is described.

Delirium After Cardiac Surgery and Cumulative Fluid Balance: A Case-Control Cohort Study.

OBJECTIVE: To assess a novel hypothesis to explain delirium after cardiac surgery through the relationship between cumulative fluid balance and delirium. This hypothesis involved an inflammatory process combined with a hypervolemic state, which could lead to venous congestion reaching the brain. DESIGN: Retrospective case-control (1:1) cohort study. SETTING: University-affiliated tertiary cardiology center. PARTICIPANTS: Cardiac surgery intensive care unit (ICU) patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Cumulative fluid balance was evaluated at 3 times: (1) upon arrival at the ICU after surgery, (2) 24 hours post-ICU arrival, and (3) 48 hours post-ICU arrival. A generalized estimated equation was used to model the association between cumulative fluid balance and delirium occurrence 24 hours later. Covariates were selected based on the statistical differences between cases and controls on delirium risk factors and clinical characteristics. The cohort included 346 patients, of which 39 (11%), 104 (30%), and 142 patients (41%) presented delirium at 24, 48, and 72 hours post-ICU arrival, respectively. The effect of time had an odds ratio (OR) of 2.14, 95% confidence interval (CI) 1.603 to 2.851, and a p value < 0.001. The cumulative fluid balance was associated with delirium occurrence (OR 1.20, 95% CI: 1.066-1.355, p = .003). History of neurological disorder, having both hearing and visual impairment, type of procedure, perioperative cerebral oximetry, mean pulmonary artery pressure pre-cardiopulmonary bypass (CPB), and mean arterial pressure post-CPB also contributed to delirium in the model. CONCLUSION: Delirium is associated with a cumulative fluid balance, but the extent through which this plays an etiologic role remains to be determined.

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.

Current Review of Implantable Cardioverter Defibrillator Use in Patients With Left Ventricular Assist Device.

PURPOSE OF REVIEW: While use of implantable cardioverter defibrillator (ICD) in patients with heart failure (HF) and reduced ejection fraction is recommended, their role in patients with left ventricular assist device (LVAD) remains controversial, especially with continuous flow (CF) devices. RECENT FINDINGS: Ventricular arrhythmias (VA) in LVAD patients are frequent and associated with worse outcomes, especially postoperatively. Data on the role of ICDs in LVAD patients are scarce, based on case reports or small retrospective series. While the majority of LVAD patients currently have an ICD, it seems that some might not derive any benefit, with additional risks in terms of inappropriate shocks, psychological distress, and infections. Some CF-LVAD patients are at high risk of VA and hemodynamic collapse; under those circumstances, an ICD might provide benefits. A randomized-controlled trial of routine ICD implantation in CF-LVAD would be needed to clarify their impact on survival in low risk patients.

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.