Hemodynamic management during off-pump coronary artery bypass surgery: a narrative review of proper targets for safe execution and troubleshooting / 대한마취과학회지

Off-pump coronary surgery requires mechanical cardiac displacement, which results in bi-ventricular systolic and diastolic dysfunction. Although transient, subsequent hemodynamic deterioration can be associated with poor prognosis and, in extreme cases, emergency conversion to on-pump surgery, which is associated with high morbidity and mortality. Thus, appropriate decision-making regarding whether the surgery can be proceeded based on objective hemodynamic targets is essential before coronary arteriotomy. For adequate hemodynamic management, avoiding myocardial oxygen supply-demand imbalance, which includes maintaining mean arterial pressure above 70 mmHg and preventing an increase in oxygen demand beyond the patient’s coronary reserve, must be prioritized. Maintaining mixed venous oxygen saturation above 60%, which reflects the lower limit of adequate global oxygen supply-demand balance, is also essential. Above all, severe mechanical cardiac displacement incurring compressive syndromes, which cannot be overcome by adjusting major determinants of cardiac output, should be avoided. An uncompromising form of cardiac constraint can be ruled out as long as the central venous pressure is not equal to or greater than the pulmonary artery diastolic (or occlusion) pressure, as this would reflect tamponade physiology. In addition, transesophageal echocardiography should be conducted to rule out mechanical cardiac displacement-induced ventricular interdependence, dyskinesia, severe mitral regurgitation, and left ventricular outflow tract obstruction with or without systolic motion of the anterior leaflet of the mitral valve, which cannot be tolerated during grafting. Finally, the ascending aorta should be carefully inspected for gas bubbles to prevent hemodynamic collapse caused by a massive gas embolism obstructing the right coronary ostium.

Impact of transient decrease in mixed venous oxygen saturation on prognosis in off-pump coronary artery bypass surgery: a retrospective cohort study / 대한마취과학회지

Background@#The prognostic consequences of transient hemodynamic deterioration due to cardiac displacement, which is most severe during left circumflex artery (LCX) grafting in off-pump coronary artery bypass surgery (OPCAB) are unknown. This study aimed to investigate the association between mixed venous oxygen saturation (SvO2) 24 h, cerebrovascular accident, and acute kidney injury. @*Results@#Among 1,071 patients, the composite of morbidity endpoints occurred in 303 (28%) patients. SvO2 < 60% during LCX grafting was significantly associated with the composite of morbidity (OR: 2.72, 95% CI [1.60, 4.61], P < 0.001) along with advanced age, chronic kidney disease, ratio of early mitral inflow velocity to mitral annular early diastolic velocity, and EuroSCORE II. Other major hemodynamic variables including the cardiac index were not associated with the outcome. Additional regression analysis revealed pre-operative anemia as a predictor of SvO2 < 60% during LCX grafting (OR: 2.09, 95% CI [1.33, 3.29], P = 0.001). @*Conclusions@#A decrease in SvO2 < 60%, albeit confined to the period of cardiac displacement, was associated with a 2.7-fold increased risk of detrimental outcomes after OPCAB, implying the prognostic importance of this transient deterioration in oxygen supply-demand balance.

Transcatheter Aortic Valve Replacement versus Sutureless Aortic Valve Replacement:A Single Center Retrospective Cohort Study

Purpose@#This study sought to compare clinical outcomes between transcatheter aortic valve replacement (TAVR) and sutureless aortic valve replacement (SU-AVR). @*Materials and Methods@#In total, 320 patients with symptomatic severe aortic stenosis who underwent TAVR (n=254) or SU-AVR (n=66) at Severance Cardiovascular Hospital between July 2011 and September 2019 were included for analysis. Propensity score matching and inverse probability weighted adjustment were performed to adjust for confounding baseline characteristics. Outcomes defined by the Valve Academic Research Consortium-2 in 62 patients pairs were compared. @*Results@#Device success (79.0% vs. 79.0%, p>0.999) and 30-day mortality (4.8% vs. 0.0%, p=0.244) did not differ between the TAVR and SU-AVR groups. The TAVR group developed more frequent mild or moderate paravalvular leakage (59.7% vs. 8.1%, p<0.001), whereas SU-AVR was associated with higher rates of major or life-threatening bleeding (9.7% vs. 22.6%, p=0.040), acute kidney injury (8.1% vs. 21.0%, p=0.041), and new-onset atrial fibrillation (4.8% vs. 32.3%. p<0.001) at 30 days, along with longer stays in the intensive care unit (ICU) (1.9±1.6 days vs. 5.9±9.2 days, p=0.009) and hospital (7.1±7.9 days vs. 13.1±8.8 days, p<0.001). The TAVR group showed a trend towards a higher 1-year all-cause mortality, compared with the SU-AVR group (7.0% vs 1.7%, p=0.149). Cardiovascular mortality, however, did not differ significantly (1.6% vs 1.7%, p=0.960). @*Conclusion@#TAVR achieved a similar 1-year survival rate free from cardiovascular mortality as SU-AVR and was associated with a lower incidence of complications, except for paravalvular leakage, and shorter stays in the ICU and hospital.

Transcatheter Aortic Valve Replacement versus Sutureless Aortic Valve Replacement:A Single Center Retrospective Cohort Study

Purpose@#This study sought to compare clinical outcomes between transcatheter aortic valve replacement (TAVR) and sutureless aortic valve replacement (SU-AVR). @*Materials and Methods@#In total, 320 patients with symptomatic severe aortic stenosis who underwent TAVR (n=254) or SU-AVR (n=66) at Severance Cardiovascular Hospital between July 2011 and September 2019 were included for analysis. Propensity score matching and inverse probability weighted adjustment were performed to adjust for confounding baseline characteristics. Outcomes defined by the Valve Academic Research Consortium-2 in 62 patients pairs were compared. @*Results@#Device success (79.0% vs. 79.0%, p>0.999) and 30-day mortality (4.8% vs. 0.0%, p=0.244) did not differ between the TAVR and SU-AVR groups. The TAVR group developed more frequent mild or moderate paravalvular leakage (59.7% vs. 8.1%, p<0.001), whereas SU-AVR was associated with higher rates of major or life-threatening bleeding (9.7% vs. 22.6%, p=0.040), acute kidney injury (8.1% vs. 21.0%, p=0.041), and new-onset atrial fibrillation (4.8% vs. 32.3%. p<0.001) at 30 days, along with longer stays in the intensive care unit (ICU) (1.9±1.6 days vs. 5.9±9.2 days, p=0.009) and hospital (7.1±7.9 days vs. 13.1±8.8 days, p<0.001). The TAVR group showed a trend towards a higher 1-year all-cause mortality, compared with the SU-AVR group (7.0% vs 1.7%, p=0.149). Cardiovascular mortality, however, did not differ significantly (1.6% vs 1.7%, p=0.960). @*Conclusion@#TAVR achieved a similar 1-year survival rate free from cardiovascular mortality as SU-AVR and was associated with a lower incidence of complications, except for paravalvular leakage, and shorter stays in the ICU and hospital.

Monitored Anesthesia Care for Cardiovascular Interventions

The interventional cardiology is growing and evolving. Many complex procedures are now performed outside the operating room to manage cardiovascular pathologies which had been traditionally treated with cardiac surgery. Appropriate sedation strategy is crucial for improved patient comfort and successful procedure while ensuring safety. Sedation for cardiovascular intervention is frequently challenging, especially in critically-ill, high-risk patients. This review addresses pre-procedure evaluation and preparation of patients, proper monitoring, commonly used sedatives and analgesics, and considerations for specific procedures. Appropriate depth of sedation and analgesia should be balanced with patient, procedural and institutional factors. Understanding of the pharmacology of sedatives/analgesics, vigilant monitoring, ability and proper preparation for management of potential complications may improve outcomes in patients undergoing sedation for cardiovascular procedures.

Perioperative management of patients receiving non-vitamin K antagonist oral anticoagulants: up-to-date recommendations

Indications of non-vitamin K antagonist oral anticoagulants (NOACs), consisting of two types: direct thrombin inhibitor (dabigatran) and direct factor Xa inhibitor (rivaroxaban, apixaban, and edoxaban), have expanded over the last few years. Accordingly, increasing number of patients presenting for surgery are being exposed to NOACs, despite the fact that NOACs are inevitably related to increased perioperative bleeding risk. This review article contains recent clinical evidence-based up-to-date recommendations to help set up a multidisciplinary management strategy to provide a safe perioperative milieu for patients receiving NOACs. In brief, despite the paucity of related clinical evidence, several key recommendations can be drawn based on the emerging clinical evidence, expert consensus, and predictable pharmacological properties of NOACs. In elective surgeries, it seems safe to perform high-bleeding risk surgeries 2 days after cessation of NOAC, regardless of the type of NOAC. Neuraxial anesthesia should be performed 3 days after cessation of NOACs. In both instances, dabigatran needs to be discontinued for an additional 1 or 2 days, depending on the decrease in renal function. NOACs do not require a preoperative heparin bridge therapy. Emergent or urgent surgeries should preferably be delayed for at least 12 h from the last NOAC intake (better if > 24 h). If surgery cannot be delayed, consider using specific reversal agents, which are idarucizumab for dabigatran and andexanet alfa for rivaroxaban, apixaban, and edoxaban. If these specific reversal agents are not available, consider using prothrombin complex concentrates.

Monitored Anesthesia Care for Cardiovascular Interventions

The interventional cardiology is growing and evolving. Many complex procedures are now performed outside the operating room to manage cardiovascular pathologies which had been traditionally treated with cardiac surgery. Appropriate sedation strategy is crucial for improved patient comfort and successful procedure while ensuring safety. Sedation for cardiovascular intervention is frequently challenging, especially in critically-ill, high-risk patients. This review addresses pre-procedure evaluation and preparation of patients, proper monitoring, commonly used sedatives and analgesics, and considerations for specific procedures. Appropriate depth of sedation and analgesia should be balanced with patient, procedural and institutional factors. Understanding of the pharmacology of sedatives/analgesics, vigilant monitoring, ability and proper preparation for management of potential complications may improve outcomes in patients undergoing sedation for cardiovascular procedures.

Anesthetic considerations for a patient with situs inversus totalis undergoing cardiac surgery: A case report

A 58-year-old male patient with situs inversus totalis, a rare congenital malformation characterized by all asymmetric organs being formed as the mirror images of their normal morphologies, underwent mitral valve repair due to mitral valve prolapse. This case was reported to suggest that anesthesiologists should thoroughly understand the anatomy of these types of patients before providing cardiac anesthesia that often requires advanced monitoring and rely on their accurate interpretation. Accordingly, a few key points will be discussed with emphasis on reversing lead placement during electrocardiogram monitoring, using the left internal jugular vein for pulmonary artery catheterization, and firmly comprehending mirror image heart morphology to better conduct transesophageal echocardiography.

Current clinical application of dexmedetomidine for sedation and anesthesia

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.

Current clinical application of dexmedetomidine for sedation and anesthesia

Many sedatives are used clinically and include benzodiazepines, barbiturates, antihistamines, propofol, and alpha-2-agonist. Benzodiazepines activate GABA neuronal receptors in the brain and present sedating, hypnotic, anxiolytic, amnestic, and anticonvulsant effects, but low analgesic effects. Propofol induce sedative, anxiolytic, and amnestic effects but no analgesic effects. However, risks such as cardiopulmonary instability and hypotension must be considered during administration. Dexmedetomidine is a high selective alpha-2 agonist and has many advantages as a sedative. Patients under dexmedetomidine sedation awaken easily and are more likely to be cooperative. Risk of respiratory depression and cardiopulmonary instability is low as well. Additionally, dexmedetomidine decreases amount of analgesic needed during and after surgery, presenting analgesic effects. Dexmedetomidine also decreases risk of delirium. However, bradycardia may occur and biphasic effects on blood pressure may be observed during beginning of administration. Because of lengthy symptom onset and offset time, physicians should carefully control administration at the beginning and end of dexmedetomidine administration. The purpose of this review is to evaluate the efficacy and availability of dexmedetomidine in various clinical fields including sedation for critically ill patients, regional anesthesia, monitored anesthesia care for some invasive procedures, stabilization of heart in cardiac surgery or endoscopic procedures.

Dual antiplatelet therapy and non-cardiac surgery: evolving issues and anesthetic implications / 대한마취과학회지

Dual antiplatelet therapy (DAPT) consisting of aspirin plus a P2Y₁₂ inhibitor (clopidogrel, prasugrel, or ticagrelor) is imperative for the treatment of acute coronary syndrome, particularly during the re-endothelialization period after percutaneous coronary intervention (PCI). When patients undergo surgery during this period, the consequences of stent thrombosis are far more serious than those of bleeding complications, except in cases of intracranial surgery. The recommendations for perioperative DAPT have changed with emerging evidence regarding the improved efficacy of non-first-generation drug (everolimus, zotarolimus)-eluting stents (DES). The mandatory interval of 1 year for elective surgery after DES implantation was shortened to 6 months (3 months if surgery cannot be further delayed). After this period, it is generally recommended that the P2Y₁₂ inhibitor be stopped for the amount of time necessary for platelet function recovery (clopidogrel 5–7 days, prasugrel 7–10 days, ticagrelor 3–5 days), and that aspirin be continued during the perioperative period. In emergent or urgent surgeries that cannot be delayed beyond the recommended period after PCI, proceeding to surgery with continued DAPT should be considered. For intracranial procedures or other selected surgeries in which increased bleeding risk may also be fatal, cessation of DAPT (possibly with continuation or minimized interruption [3–4 days] of aspirin) with bridge therapy using short-acting, reversible intravenous antiplatelet agents such as cangrelor (P2Y₁₂ inhibitor) or glycoprotein IIb/IIIa inhibitors (tirofiban, eptifibatide) may be contemplated. Such a critical decision should be individually tailored based on consensus among the anesthesiologist, cardiologist, surgeon, and patient to minimize both ischemic and bleeding risks.

Efficacy of Goal-Directed Therapy Using Bioreactance Cardiac Output Monitoring after Valvular Heart Surgery

PURPOSE: We compared the efficacy of postoperative hemodynamic goal-directed therapy (GDT) using a pulmonary artery catheter (PAC) and bioreactance-based noninvasive cardiac output monitoring (NICOM) in patients with atrial fibrillation undergoing valvular heart surgery. MATERIALS AND METHODS: Fifty eight patients were randomized into two groups of GDT with common goals to maintain a mean arterial pressure of 60-80 mm Hg and cardiac index > or =2 L/min/m2: the PAC group (n=29), based on pulmonary capillary wedge pressure, and the NICOM group (n=29), based on changes in stroke volume index after passive leg raising. The primary efficacy variable was length of hospital stay. Secondary efficacy variables included resource utilization including vasopressor and inotropic requirement, fluid balance, and major morbidity endpoints. RESULTS: Patient characteristics and operative data were similar between the groups, except that significantly more patients underwent double valve replacement in the NICOM group. The lengths of hospital stay were not different between the two groups (12.2+/-4.8 days vs. 10.8+/-4.0 days, p=0.239). Numbers of patients requiring epinephrine (5 vs. 0, p=0.019) and ventilator care >24 h (6 vs. 1, p=0.044) were significantly higher in the PAC group. The PAC group also required significantly larger amounts of colloid (1652+/-519 mL vs. 11430+/-463 mL, p=0.004). CONCLUSION: NICOM-based postoperative hemodynamic GDT showed promising results in patients with atrial fibrillation undergoing valvular heart surgery in terms of resource utilization.

Persistent Left Superior Vena Cava Detected Incidentally after Pulmonary Artery Catheterization / 대한중환자의학회지

We present a case of pulmonary artery catheter (PAC) placement through the right internal jugular vein, bridging vein and coronary sinus in a patient with previously unrecognized persistent left superior vena cava (LSVC) and diminutive right superior vena cava. A 61-year-old male patient was scheduled for mitral valve repair for regurgitation. Preoperative transthoracic echocardiography revealed dilated coronary sinus, but no further evaluations were performed. During advancement of the PAC, right ventricular and pulmonary arterial pressure tracing was observed at 50 and 60 cm, respectively. Transesophageal echocardiography ruled out intracardiac knotting and revealed the presence of the PAC in the LSVC, entering the right ventricle from the coronary sinus. Diminutive right superior vena cava was observed after sternotomy. The PAC was left in place for 2 days postoperatively without any complications. This case emphasizes that the possibility of LSVC and associated anomalies should always be ruled out in patients with dilated coronary sinus.

Persistent Left Superior Vena Cava Detected Incidentally after Pulmonary Artery Catheterization / 대한구급학회지

We present a case of pulmonary artery catheter (PAC) placement through the right internal jugular vein, bridging vein and coronary sinus in a patient with previously unrecognized persistent left superior vena cava (LSVC) and diminutive right superior vena cava. A 61-year-old male patient was scheduled for mitral valve repair for regurgitation. Preoperative transthoracic echocardiography revealed dilated coronary sinus, but no further evaluations were performed. During advancement of the PAC, right ventricular and pulmonary arterial pressure tracing was observed at 50 and 60 cm, respectively. Transesophageal echocardiography ruled out intracardiac knotting and revealed the presence of the PAC in the LSVC, entering the right ventricle from the coronary sinus. Diminutive right superior vena cava was observed after sternotomy. The PAC was left in place for 2 days postoperatively without any complications. This case emphasizes that the possibility of LSVC and associated anomalies should always be ruled out in patients with dilated coronary sinus.

Echocardiographic detection of left atrial mobile calcium debris of trido valve surgery: a case report / 대한마취과학회지

Calcification of the cardiac chambers is among the challenges associated with reoperative cardiac surgeries by increasing the risk of systemic embolization. We experienced a case of an unexpected detected mass by intraoperative transesophageal echocardiography during weaning from cardiopulmonary bypass in a patient undergoing trido mitral and tricuspid valve replacement surgery. The surgically removed mass was identified as calcified tissue. This case shows the importance of careful echocardiographic evaluation of the left heart in patients undergoing repeat valve surgery given their greater potential for embolic sources.

Transcatheter Aortic Valve Implantation in a Patient with Previous Mitral Valve Replacement

Transcatheter aortic valve implantation (TAVI) has shown favorable outcomes in patients with severe symptomatic aortic valve stenosis who are at high surgical risk or are unsuitable candidates for open heart surgery. However, concerns exist over treating patients who have previously undergone mitral valve surgery due to the potential interference between the mitral prosthetic valve or ring and the TAVI device. In this case report, we present a patient with symptomatic severe aortic stenosis and previous mechanical mitral valve replacement who was successfully treated with TAVI using a CoreValve.

Successful Treatment of Severe Aortic Stenosis With Transcatheter Aortic Valve Implantation in a Centenarian Patient

Transcatheter aortic valve implantation (TAVI) is a less invasive procedure to treat severe aortic valve stenosis than conventional surgical aortic valve replacement. Furthermore, TAVI has shown similar clinical outcomes as surgical treatment with less mortality and morbidities in elderly patients at high risk for conventional surgery. In this report, we describe case of successful TAVI using a CoreValve in a 103-year-old patient with symptomatic severe aortic valve stenosis.

Effect of 6% Hydroxyethyl Starch 130/0.4 as a Priming Solution on Coagulation and Inflammation Following Complex Heart Surgery

PURPOSE: Prolonged duration of cardiopulmonary bypass aggravates the degree of inflammation and coagulopathy. We investigated the influence of 6% hydroxyethyl starch (HES) 130/0.4 on coagulation and inflammation compared with albumin when used for both cardiopulmonary bypass priming and perioperative fluid therapy in patients undergoing complex valvular heart surgery. MATERIALS AND METHODS: Fifty four patients were randomly allocated into albumin-HES, albumin-nonHES, and HES-HES groups. The cardiopulmonary bypass circuit was primed with 5% albumin in the albumin-HES and albumin-nonHES group, and with HES in the HES-HES group. As perioperative fluid, only plasmalyte was used in the albumin-nonHES group whereas HES was used up to 20 mL/kg in the albumin-HES and albumin-HES group. Serial assessments of coagulation profiles using the rotational thromboelastometry and inflammatory markers (tissue necrosis factor-alpha, interleukin-6, and interleukin-8) were performed. RESULTS: Patients' characteristics and the duration of cardiopulmonary bypass (albumin-HES; 137+/-34 min, HES-HES; 136+/-47 min, albumin-nonHES; 132+/-39 min) were all similar among the groups. Postoperative coagulation profiles demonstrated sporadic increases in clot formation time and coagulation time, without any differences in the actual amount of perioperative bleeding and transfusion requirements among the groups. Also, inflammatory markers showed significant activation after cardiopulmonary bypass without any differences among the groups. CONCLUSION: Even in the presence of prolonged duration of cardiopulmonary bypass, HES seemed to yield similar influence on the ensuing coagulopathy and inflammatory response when used for priming and perioperative fluid therapy following complex valvular heart surgery compared with conventional fluid regimen including albumin and plasmalyte.

Isolated central venous pressure elevation caused by hematoma formation compressing the superior vena cava following a Bentall operation: a case report / 대한마취과학회지

We present a case of a patient exhibiting isolated elevation of the central venous pressure with minimal hemodynamic deterioration in an immediate postoperative period after Bentall operation requiring re-exploration. Isolated elevation of the central venous pressure usually alerts physicians of a volume overload or right ventricular dysfunction. However, even in the absence of significant hemodynamic deterioration, the development of loculated hematoma that compresses the superior vena cava should be ruled out, as it can be life-threatening through the formation of cerebral and laryngeal edema, similar to superior vena cava syndrome. This case emphasizes the importance of a prompt differential diagnosis of the isolated central venous pressure elevation after cardiac surgery with transesophageal echocardiography for the administration of appropriate treatment.

The Influence of Hypothermia on Transfusion Requirement in Patients Who Received Clopidogrel in Proximity to Off-Pump Coronary Bypass Surgery

PURPOSE: Hypothermia adversely affects the coagulation that could be of clinical significance in patients receiving clopidogrel. We evaluated the influence of hypothermia on transfusion requirements in patients undergoing isolated off-pump coronary artery bypass surgery (OPCAB) who continued clopidogrel use within 5 days of surgery. MATERIALS AND METHODS: Protocol-based, prospectively entered data of 369 patients were retrospectively reviewed. The time-weighted average of intraoperative temperatures and the temperature upon ICU admission (TWA-temp) was assessed. Patients were divided into normothermia (> or =36degrees C, n=224) and hypothermia (<36degrees C, n=145) group. The transfusion requirement for perioperative blood loss was assessed and compared. RESULTS: Patients with hypothermia were older and had lower body surface area (BSA) than patients with normothermia. Age and BSA adjusted transfusion requirement was significantly larger in the hypothermia group [patients requiring transfusion: 64% versus 48%, p=0.003; number of units: 0 (0-2) units versus 2 (0-3) units, p=0.002]. In multivariate analysis of predictors of perioperative multiple transfusion requirements, hypothermia was identified as an independent risk factor along with age, female gender, BSA, chronic kidney disease, and congestive heart failure. CONCLUSION: Hypothermia was associated with increased transfusion requirement in patients undergoing OPCAB who received clopidogrel in proximity to surgery. Considering the high prevalence and the possibility of hypothermia being a modifiable risk factor, aggressive measures should be undertaken to maintain normothermia in those patients.