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.

Perioperative implication of the endothelial glycocalyx / 대한마취과학회지

The endothelial glycocalyx (EG) is a gel-like layer lining the luminal surface of healthy vascular endothelium. Recently, the EG has gained extensive interest as a crucial regulator of endothelial funtction, including vascular permeability, mechanotransduction, and the interaction between endothelial and circulating blood cells. The EG is degraded by various enzymes and reactive oxygen species upon pro-inflammatory stimulus. Ischemia-reperfusion injury, oxidative stress, hypervolemia, and systemic inflammatory response are responsible for perioperative EG degradation. Perioperative damage of the EG has also been demonstrated, especially in cardiac surgery. However, the protection of the EG and its association with perioperative morbidity needs to be elucidated in future studies. In this review, the present knowledge about EG and its perioperative implication is discussed from an anesthesiologist's perspective.

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.

Intraoperative paravalvular leakage after sutureless aortic valve replacement corrected with secondary balloon dilatation: A case report

Sutureless aortic valve replacement was performed in a 72-year-old female patient with severe aortic stenosis who had undergone coronary revascularization and pacemaker implantation. After valve excision, decalcification was deliberately incompletely performed at the commissure of the left- and non-coronary cusp to obtain a regular and circular annular margin. After implantation of the stented valve, no paravalvular leakage was noted on water irrigation testing. Upon weaning from cardiopulmonary bypass, a moderate degree of paravalvular leakage was observed by transesophageal echocardiography at the junction of the left- and non-coronary cusp. Instead of removing the valve and performing more complete decalcification to implant a larger valve, secondary balloon dilatation and warm sterile water irrigation were performed to allow further expansion and fixing of the metal alloy stent around the aortic wall to minimize the duration of aortic cross-clamp. No paravalvular leakage was observed thereafter and the patient was discharged without any complications.

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.

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.

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.

Effects of ulinastatin on coagulation in high-risk patients undergoing off-pump coronary artery bypass graft surgery / 대한마취과학회지

BACKGROUND: Both systemic inflammatory reaction and regional myocardial ischemia/reperfusion injury may elicit hypercoagulability after off-pump coronary artery bypass grafting (OPCAB). We investigated the influence of ulinastatin, which suppresses the activity of polymorphonuclear leukocyte elastase and production of pro-inflammatory cytokines, on coagulation in patients with elevated high-sensitivity C-reactive protein (hsCRP) undergoing OPCAB. METHODS: Fifty patients whose preoperative hsCRP > 3.0 mg/L were randomly allocated into the ulinastatin (600,000 U) or control group. Serum concentrations of thrombin-antithrombin complex (TAT) and prothrombin fragment 1+2 (F1+2) were measured preoperatively, immediately after surgery, and at 24 h after surgery, respectively. Secondary endpoints included platelet factor (PF)-4, amount of blood loss, and transfusion requirement. RESULTS: All baseline values of TAT, F1+2, and PF-4 were higher than the normal range in both groups. F1+2 was elevated in both groups at immediate, and at 24 h after surgery as compared to baseline value, without any significant intergroup differences. Remaining coagulation parameters, transfusion requirement and blood loss during operation and postoperative 24 h were not different between the two groups. CONCLUSIONS: Intraoperative administration of ulinastatin did not convey beneficial influence in terms of coagulation and blood loss in high-risk patients with elevated hsCRP undergoing multivessel OPCAB, who already exhibited hypercoagulability before surgery.

Optimal Anticoagulation during Off Pump Coronary Artery Bypass in Patients Recently Exposed to Clopidogrel

PURPOSE: The aim of this study was to find an optimal range of activated clotting time (ACT) during off-pump coronary artery bypass surgery (OPCAB) yielding ischemic protection without the risk of hemorrhagic complications in patients with recent exposure to dual antiplatelet therapy. MATERIALS AND METHODS: Three hundred and five patients who received aspirin and clopidogrel within 7 days of isolated multi-vessel OPCAB were retrospectively studied. Combined hemorrhagic and ischemic outcome was defined as the occurrence of 1 of the following: significant perioperative bleeding (>30% of estimated blood volume), transfusion of packed red blood cell (pRBC) > or =2 U, or myocardial infarction (MI). This was compared in relation to the tertile distribution of the time-weighted average ACT-212-291 sec (first tertile), 292-334 sec (second tertile), 335-485 sec (third tertile). RESULTS: The amount of perioperative blood loss was 937+/-313 mL, 1014+/-340 mL, and 1076+/-383 mL, respectively (p=0.022). Significantly more patients in the third tertile developed MI (4%, 4%, and 12%, respectively, p=0.034). The incidence of significant perioperative blood loss and transfusion of pRBC > or =2 U were lower in the first tertile than those of other tertiles without statistical significance. In the multivariate analysis, the first tertile was associated with a 52% risk reduction of combined hemorrhagic and ischemic outcomes (95% confidence interval: 0.25-0.92, p=0.027). CONCLUSION: A lower degree of anticoagulation with a reduced initial heparin loading dose should be carefully considered for patients undergoing OPCAB who have recently been exposed to clopidogrel.

Formation of intracardiac thrombus during cardiopulmonary bypass despite full heparinization and adequate activated clotting time: A case report / 대한마취과학회지

We reports a case of a newly formed thrombus in the left atrial appendage during cardiopulmonary bypass detected by transesophageal echocardiography in a patient with chronic atrial fibrillation and mitral stenosis. This case alerts the anesthesiologists of possible thrombus formation despite full heparinization during cardiac surgery and the importance of a comprehensive echocardiography examination.

Effect of a single bolus of methylene blue prophylaxis on vasopressor and transfusion requirement in infective endocarditis patients undergoing cardiac surgery / 대한마취과학회지

BACKGROUND: The accentuated nitric oxide (NO) release that is induced by the systemic inflammatory response associated with infective endocarditis (IE) and cardiopulmonary bypass (CPB) may result in catecholamine refractory hypotension (vasoplegia) and increased transfusion requirement due to platelet inhibition. Methylene blue (MB) is an inhibitory drug of inducible NO. We aimed to evaluate the effect of prophylactic MB administration before CPB on vasopressor and transfusion requirements in patients with IE undergoing valvular heart surgery (VHS). METHODS: Forty-two adult patients were randomly assigned to receive 2 mg/kg of MB (MB group, n = 21) or saline (control group, n = 21) for 20 min before the initiation of CPB. The primary end points were comparisons of vasopressor requirements serially assessed after weaning from CPB and hemodynamic parameters serially recorded before and after CPB. The secondary endpoint was the comparison of transfusion requirements. RESULTS: Two patients in the control group received MB after weaning from CPB due to norepinephrine and vasopressin refractory vasoplegia and were thus excluded. There were no significant differences in vasopressor requirements and hemodynamic parameters between the two groups. The mean number of units of packed erythrocytes transfused per transfused patient was significantly less in the MB group. The numbers of patients transfused with fresh frozen plasma and platelet concentrates were less in the MB group. CONCLUSIONS: In IE patients undergoing VHS, prophylactic MB administration before CPB did not confer significant benefits in terms of vasopressor requirements and hemodynamic parameters, but it was associated with a significant reduction in transfusion requirement.

The effect of milrinone on the intraoperative hemodynamics during off-pump coronary bypass surgery in patients with an elevated echocardiographic index of the ventricular filling pressure / 대한마취과학회지

BACKGROUND: Hemodynamic derangement during off-pump coronary artery bypass surgery (OPCAB) is mainly attributed to impaired filling and diastolic dysfunction. An elevated ratio of the mitral velocity to the early-diastolic velocity of the mitral annulus (E/e' > 15) is a relatively new indicator of diastolic function, and this was reported to be associated with impaired hemodynamics during OPCAB. We investigated the efficacy of milrinone on the perioperative hemodynamics and short term outcomes of patients with an E/e' > 15 and who underwent OPCAB. METHODS: The patients were randomly allocated into either group C (control, n = 31) or group M (n = 31) and they were treated with the same amount of either normal saline or milrinone (0.5 microg/kg/min) without bolus loading after completion of internal mammary artery harvest until the end of operation. Hemodynamic measurements were recorded after the induction of anesthesia (T1), 5 min after starting each distal anastomosis of the left anterior descending artery (T2), left circumflex artery (T3) and right coronary artery (T4), and 5 min after sternum closure (T5). RESULTS: The mixed venous oxygen saturation (SvO2) was lower through T2-T4 compared to the baseline value in both groups, while the degree of the decrease was significantly less in group M than that in group C. The other hemodynamic variables, the operative data and the postoperative outcomes were similar between the two groups. CONCLUSIONS: Intraoperative infusion of milrinone did not significantly improve the perioperative hemodynamics and the subsequent short term outcomes for the patients with preexisting diastolic dysfunction as represented by an elevated E/e' value, although it reduced the degree of decrease of the SvO2 during OPCAB.

The uncalibrated pulse contour cardiac output during off-pump coronary bypass surgery: performance in patients with a low cardiac output status and a reduced left ventricular function / 대한마취과학회지

BACKGROUND: We compared the continuous cardiac index measured by the FloTrac/Vigileo(TM) system (FCI) to that measured by a pulmonary artery catheter (CCI) with emphasis on the accuracy of the FCI in patients with a decreased left ventricular ejection fraction (LVEF) and a low cardiac output status during off-pump coronary bypass surgery (OPCAB). We also assessed the influence of several factors affecting the pulse contour, such as the mean arterial pressure (MAP), the systemic vascular resistance index (SVRI) and the use of norepinephrine. METHODS: Fifty patients who were undergoing OPCAB (30 patients with a LVEF > or = 40%, 20 patients with a LVEF < 40%) were enrolled. The FCI and CCI were measured and we performed a Bland-Altman analysis. Subgroup analyses were done according to the LVEF (< 40%), the CCI (< or = 2.4 L/min/m), the MAP (60-80 mmHg), the SVRI (1,600-2,600 dyne/s/cm5/m2) and the use of norepinephrine. RESULTS: The FCI was reliable at all the time points of measurement with an overall bias and limit of agreement of -0.07 and 0.67 L/min/m2, respectively, resulting in a percentage error of 26.9%. The percentage errors in the patients with a decreased LVEF and in a low cardiac output status were 28.2% and 22.3%, respectively. However, the percentage error in the 91 data pairs outside the normal range of the SVRI was 40.2%. CONCLUSIONS: The cardiac output measured by the FloTrac/Vigileo(TM) system was reliable even in patients with a decreased LVEF and in a low cardiac output status during OPCAB. Acceptable agreement was also noted during the period of heart displacement and grafting of the obtuse marginalis branch.

The Effect of Stellate Ganglion Block on the Treatment of Idiopathic Sudden Sensorineural Hearing Loss / 대한마취과학회지

BACKGROUND: Idiopathic sudden sensorineural hearing loss (ISSNHL) is defined as a sensorineural hearing loss which develops abruptly without definitive causes. Stellate ganglion block (SGB) has been used as one of the treatment modalities in ISSNHL. However, published data establishing the effect of SGB has been slim. We conducted this study to evaluate the effect of SGB according to the factors that may influence the prognosis of the disease. METHODS: We reviewed the records of 343 patients. The control group was managed with medications, and the SGB group was managed with SGB and the same medications. SGB was performed with 5 ml of 1.0% mepivacaine. The pure-tone audiogram was performed after the therapy and Siegel's criteria was used to define the recovery of hearing. RESULTS: The recovery rate of the SGB group was higher than that of the control group (58.1% vs. 42.1%, P < 0.05). The SGB group had a higher recovery rate than the control group in patients treated within 7 days from the onset of symptoms (66.9% vs. 44.1%, P < 0.05), without diabetes mellitus (58.5% vs. 44.9%, P < 0.05), without dizziness (61.6% vs. 44.6%, P < 0.05), or whose initial hearing loss was between 71 and 90 dB (69.4% vs. 38.9%, P < 0.05). CONCLUSIONS: SGB is thought to be a useful therapy for ISSNHL, especially in the patients treated within 7 days, without diabetes mellitus, dizziness, or whose initial hearing loss was severe.

Hemodynamic Effects of Modified Ultrafiltration (MUF) in Adult Patients Undergoing Valvular Heart Surgery / 대한마취과학회지

BACKGROUND: Modified ultrafiltration (MUF) has been demonstrated to have beneficial effects in children undergoing cardiac surgery with cardiopulmonary bypass (CPB). In adults, the hemodynamic effects of MUF are little known. The purpose of this investigation is to evaluate the hemodynamic effects of MUF in adult patients undergoing valvular heart surgery. METHODS: 30 patients scheduled for elective mitral valvular surgery were randomized into either Ultrafiltration (U) or Control (C) group. In the U group, MUF was performed just after termination of CPB for 20 minutes, and not in the C group. Measurements of hemodynamic variables including right ventricular ejection fraction (RVEF) measured by thermodilution technique and hematocrit were performed before induction, just after termination of CPB, after completion of MUF and after sternal closure. Measurement after MUF in the C group was performed at 20 minutes after the termination of CPB. After transfer to ICU, same measurements were performed at postoperative 6 and 12 hrs. RESULTS: After MUF, RVEF (P < 0.05) and hematocrit (P < 0.01) increased in the U group, compared to the corresponding values measured just after termination of CPB. However, the variables were not statistically different between the two groups throughout the intraoperative procedures and during ICU stay. CONCLUSIONS: Conclusively, MUF was demonstrated to have the transient beneficial effect of improving the right heart function and hemoconcentration immediately after termination of CPB.

Rupture of the Myocardium during the Removal of the Cardiac Pacemaker Electrode: A case report / 대한마취과학회지

Infection of pacemaker electrode is one of the most frequent causes for the removal of the permanent cardiac pacemaker electrode and it is dangerous to remove the infected electrode by external traction method because the electrode is adhered to the myocardium. In this case, surgeon tried to remove infected cardiac pacing electrode using continuous external traction method. Myocardial rupture and consequent cardiac tamponade suddenly developed because the electrode was pulled by force. Emergent cardiopulmonary bypass was initiated and then, ruptured myocardium was repaired and the remaining electrode was removed without remarkable complications. This case emphasizes the risk of the myocardial rupture and the importance of preparing for emergent situation which can occur during the removal of the permanent pacemaker electrode, especially when the reason for the removal is the infection.