Cyanide toxicity during cardiopulmonary bypass with small dose of nitroprusside: a case report / 대한마취과학회지

Sodium nitroprusside (SNP) is an anti-hypertensive drug, commonly used to decrease the systemic vascular resistance and lower the blood pressure. When the amount of cyanide generated by the SNP exceeds the metabolic capacity for detoxification, cyanide toxicity occurs. Under general anesthesia and cardiopulmonary bypass (CPB), it may be difficult to detect the development of cyanide toxicity. In cardiac surgical patients, hemolysis, hypothermia and decreased organ perfusion, which emphasize the risk of cyanide toxicity, may develop as a consequence of CPB. In particular, hemolysis during CPB may cause an unexpected overproduction of cyanide due to free hemoglobin release. We experienced a patient who demonstrated SNP tachyphylaxis and cyanide toxicity during CPB, even though the total amount of SNP administered was much lower than the recommended dose. We therefore report this case with a review of the relevant literature.

Malposition of central venous catheter in the jugular venous arch via external jugular vein: a case report / 대한마취과학회지

The central venous cannulation is commonly performed in the operating rooms and intensive care units for various purposes. Although the central venous catheter (CVC) is used in many ways, the malpositioning of the CVC is often associated with serious complications. We report a case of an unexpected malposition of a CVC in the jugular venous arch via external jugular vein.

Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites / 대한마취과학회지

BACKGROUND: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. METHODS: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. RESULTS: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. CONCLUSIONS: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.

Resolution of peripheral artery catheter-induced ischemic injury in infants: Two case reports / 대한마취과학회지

The occurrence of catheter-induced vasospasm of small caliber arteries is a well known complication of arterial catheterization in neonates. However, there is rare publication about these complications in infants. We report infants with peripheral ischemia caused by arterial catheterization of the femoral artery.

Occlusion of the right subclavian artery after insertion of a transesophageal echocardiography probe in an adult with a vascular ring: A case report / 대한마취과학회지

Intraoperative transesophageal echocardiography (TEE) has become an important monitoring device for patients undergoing cardiac or noncardiac surgery. Complications associated with TEE are unusual, but the potential for TEE probe compression of the posterior vascular structures has been reported in pediatric patients. We present here a case of occlusion of the right subclavian artery in an adult patient with a vascular ring after insertion of a TEE probe.

Mobitz type I atrioventricular block induced by atrial pacing in a patient undergoing off-pump coronary artery bypass surgery: A case report

We report a case of Mobitz type I atrioventricular block induced by atrial pacing in a 60 year old woman undergoing off-pump coronary artery bypass surgery. Reversible ischemic damage to the conduction system might be associated with this phenomenon.

Intravalvular regurgitation of the mitral bioprosthetic valve detected by intraoperative transesophageal echocardiography : A case report / 대한마취과학회지

Intraoperative transesophageal echocardiography (IOTEE) is an invaluable diagnostic method for management of cardiac surgical patients, including patients undergoing valve replacement surgery. We report a patient who underwent reoperation for mitral valve replacement due to intravalvular regurgitation following mitral valve replacement with a bioprosthetic valve. The condition was detected by IOTEE and caused by suture entrapment.

Asystole induced by laryngosopy and tracheal intubation after induction of general anesthesia: A case report / 대한마취과학회지

Vagal reflex during laryngosopy and tracheal intubation may result in cardiac arrhythmia such as bradyarrhythmia and asystole. A 66-year-old woman, scheduled for coronary artery bypass surgery, received intravenous bolus of midazolam 2 mg, sufentanil 50 microgram, and vecuronium 10 mg for induction of general anesthesia. After two minutes of manual ventilation, tracheal intubation was attempted and the patient became asystolic during laryngoscopic manipulation. The laryngoscope was immediately withdrawn, and the patient returned to normal sinus rhythm. Ten minutes later, more experienced practitioner performed the second laryngoscopic intubation, but it eventually induced asystole again. External cardiac massage was commenced and normal sinus rhythm retuned at a rate of 60 beats/min after 1-2 minute later.

The anesthetic management of a venous bullet embolism to the right ventricle: A case report / 대한마취과학회지

Bullet embolism is a rare complication of non-penetrating gunshot trauma. There are two types of bullet embolisms: arterial and venous. Accurate preoperative localization of the bullet is important for selecting the proper surgical and anesthetic techniques. We report here on a rare case of venous bullet embolus to the right ventricle from the right iliac vein, as was demonstrated by transesophageal echocardiography.

Compromised Ventilation Caused by Transesophageal Echocardiography Probe in Pediatric Patients Undergoing Congenital Heart Surgery: A case report / 대한마취과학회지

Intraoperative transesophageal echocardiography (TEE) has become an important monitoring device for patients undergoing repair of congenital heart disease. TEE allows preoperative assessment of ventricular volume and function, pre and postoperative anatomy and the existence of intracardiac air. Although complications associated with TEE are infrequent, interference with ventilation as a result of direct compression of the endotracheal tube, distal trachea, or mainstem bronchi has been reported. Here, we report two cases of intraoperative ventilation interference caused by the TEE probe.

Changes in hemodynamic parameters and regional myocardial perfusion measured by thermal diffusion probe from the infusion of norepinephrine during displacement of porcine beating heart / 대한마취과학회지

BACKGROUND: This study was done to evaluate the sole effect of norepinephrine on the regional myocardial perfusion during displacement of the porcine beating heart using thermal diffusion method. METHODS: Thermal diffusion probe was inserted into the anterior myocardial wall during 20 procedures in 10 male pigs (30-35 kg). The measurements of regional myocardial perfusion and hemodynamic parameters were performed after complete instrumentation (baseline), after displacement of the beating heart anteriorly, and 5 and 15 minutes after norepinephrine infusion, titrated to restore baseline mean arterial pressure (MAP). RESULTS: Norepinephrine infusion reversed the decrease in MAP and myocardial perfusion, caused by displacement of the beating heart (62 +/- 3% to 115 +/- 4% of baseline, P < 0.01; 41 +/- 5% to 125 +/- 4% of baseline, P < 0.05, respectively). CONCLUSIONS: Restoration of MAP with norepinephrine infusion without any preload augmentation reversed deterioration in regional myocardial perfusion during displacement of the porcine beating heart.

Weaning Approach with Weaning Index for Postoperative Patients with Mechanical Ventilator Support in the ICU / 대한마취과학회지

BACKGROUND: The weaning index is a useful tool for avoiding the detrimental consequences of weaning failure, rapidly identifying patients who are potentially ready for spontaneous breathing, and accelerating the process of liberation from mechanical ventilation. This study examined the use of the weaning index as a weaning and extubation predictor in postoperative patients on mechanical ventilatory support in an intensive care unit (ICU). METHODS: Mechanical ventilation was discontinued in patients through pressure support ventilation (PSV), and a T-piece was applied to 169 patients. The success or failure of the weaning process was evaluated according to the preoperative conditions of the patient and their weaning indices, such as the rapid shallow breathing index (RSBI), vital capacity, inspiratory pressure. The duration of mechanical ventilation and the length of stay in the ICU and the hospital were recorded. RESULTS: Weaning from mechanical ventilatory support and extubation was performed successfully in 94.6% of patients. Sixty minutes after applying the T-piece, the PaO2/FiO2 ratio (P/F ratio) was significantly higher and the RSBI was significantly lower in the weaning success group than in the weaning failure group. The ASA class and the percentage of emergency procedures were significantly lower (p < 0.05) in the weaning success group. CONCLUSIONS: Not only the weaning index as RSBI but also P/F ratio, ASA class and emergency status need to be considered for successful weaning and extubation in postoperative ICU patients on mechanical ventilator support.

Early Hemodynamic Changes and Short-term Outcomes of Mitral Valvuloplasty versus Replacement with Chordal Preservation for Patients with Mitral Regurgitation / 대한흉부외과학회지

BACKGROUND: Preserving the subvalvular apparatus after mitral valve replacement (MVR) results in better ventricular function and a better outcome. In conjunction, mitral valve repair (MVr) is associated with a better outcome, yet little is known about the hemodynamics and outcomes between patients undergoing MVr and MVR with chordal preservation. We prospectively evaluated the hemodynamic changes and outcomes of patients undergoing MVr and MVR with chordal preservation. MATERIAL AND METHOD: Fifty-four patients with mitral regurgitation (MR) who underwent MVR with chordal preservation (n=21) or MVr (n=33) were studied. The patients' characteristics, the intra- and postoperative hemodynamics and the use of cardiac medications, the postoperative outcome and the complications were recorded during the hospital stay. All the patients were followed up for at least 6 months postoperatively for determining their morbidity and mortality. RESULT: The patients' characteristics were similar between the groups, except for the presence of atrial fibrillation and congestive heart failure which was more frequent in the MVR group. Also, the preoperative left ventricular ejection fraction was lower in the MVR group than in the MVr group (64+/-9% versus 69+/-5%, respectively, p=0.043). There were no significant differences of the hemodynamics between the groups. The use of inotropic drugs and pacemakers during the 12hrs postoperatively was more common in the MVR group than in the MVr group (48% versus 24%, p=0.025 and 52% versus 24%, p=0.035, respectively). The other postoperative outcomes were similar in both groups for at least the 6 months follow-up period. CONCLUSION: MVR with chordal preservation was comparable with regard to the hemodynamics and clinical outcomes, supporting the beneficial effect of preserving the subvalvular apparatus after MVR.

Anesthesia for Robotic Repair of the Atrial Septal Defect : A case report / 대한마취과학회지

Minimally invasive cardiac surgery including robotic technique has become increasingly popular over the last decade. The advantages of such technique include improved cosmesis and healing, and reduced stress response, hospital and intensive care unit stay, and transfusion requirements. Robot-assisted cardiac surgery requires prolonged one-lung ventilation to optimize exposure. Remote-access perfusion requires appropriate positioning of multiple catheters to establish cardiopulmonary bypass. Carbon dioxide insufflation into the thorax can cause hemodynamic instability and carbon dioxide embolism. Limited exposure of the heart may pose difficulties with management of arrhythmia, hemostasis, myocardial protection and de-airing at the end of surgery. Limited access due to robot manipulator would make rapid intervention for cardiopulmonary resuscitation difficult or impossible. This case report describes robot-asssisted atrial septal defect repair and discusses the anesthetic issues associated with minimally invasive cardiac surgery including robotic cardiac surgery.

The Effect of Milrinone on the Right Ventriclular Function in Patients with Reduced Right Ventricular Function Undergoing Off-pump Coronary Artery Bypass Graft Surgery

This investigation evaluated the effect of continuous milrinone infusion on right ventriclular (RV) function during off-pump coronary artery bypass graft (OPCAB) surgery in patients with reduced RV function. Fifty patients scheduled for OPCAB, with thermodilution RV ejection fraction (RVEF) <35% after anesthesia induction, were randomly allocated to either milrinone (0.5 microgram/kg/min) or control (saline) group. Hemodynamic variables and RV volumetric data measured by thermodilution method were collected as follows: after anesthesia induction (T1); 10 min after heart displacement for obtuse marginal artery anastomosis (T2); after pericardial closure (T3). Cardiac index and heart rate increased and systemic vascular resistance significantly decreased in milrinone group at T2. Initially lower RVEF of milrinone group was eventually comparable to control group after milrinone infusion. RVEF did not significantly change at T2 and T3 in both groups. RV end-diastolic volume in milrinone group consistently decreased from the baseline at T2 and T3. Continuous infusion of milrinone without a bolus demonstrated potentially beneficial effect on cardiac output and RV afterload in patients with reduced RV function during OPCAB. However, aggressive augmentation of intravascular volume seems to be necessary to maximize the effect of the milrinone in these patients.

Comparison of Tranesophageal Echocardiography versus Thermodilution Method for the Assessments of Right Ventricular Function / 대한마취과학회지

BACKGROUND: It is important to evaluate the right ventricular (RV) function intraoperatively for optimal management of patients undergoing cardiac surgery. The clinical relevance of thermodilution method to tranesophageal echocardiography (TEE) for the measurements of RV function during off-pump coronary artery bypass surgery (OPCAB) was evaluated in this study. METHODS: Fifty patients undergoing OPCAB were included. RV function was assessed with both thermodilution method and TEE after anesthesia induction (T1), 10 min after leg elevation (T2), 10 min after returning to the supine position (T3), 10 min after Y-graft formation started (T4), 10 min after sternum closure (T5) and 10 min after applying 5 cmH2O of positive end expiratory pressure (T6). Fractional area change (FAC) and tricuspid annular plane systolic excursion ratio (TAPSE) were measured by TEE and compared to RV ejection fraction (RVEF) measured by thermodilution technique. RV end diastolic area (EDA) derived from TEE was compared to RV end diastolic volume index (EDVI) derived from thermodilution technique. RESULTS: There was no significant correlation between echocardiographic data and thermodilution data by linear regression analysis. However, only in patients with right coronary artery stenosis less than 90%, TAPSE and FAC were significantly correlated with RVEF (P = 0.008 and 0.01, respectively) and EDA was significantly correlated with EDVI (P = 0.013) only at T4. CONCLUSIONS: RV performance measured by thermodilution technique did not correlate well with TEE finding in severe coronary artery disease patients. The correlation was significant during hemodynamically stable period (during Y-graft formation) in patients without severe right coronary artery disease.

The Effect of Right Coronary Artery Stenosis on Right Ventricular Function in Patients Undergoing off Pump Coronary Artery Bypass Surgery / 대한마취과학회지

BACKGROUND: Right ventricular (RV) function has important prognostic implications in off-pump coronary artery bypass surgery (OPCAB). This study investigated the effect of the extent of right coronary artery (RCA) stenosis on RV function and hemodynamics in patients undergoing OPCAB. METHODS: Fifty five patients undergoing OPCAB were divided into two groups according to the degree of RCA stenosis; patients with RCA stenosis of or = 80% (Group 2, n = 29). RV ejection fraction (RVEF) and RV volumetric parameters were measured using thermodilution technique. Hemodynamic variables were recorded 5 min after induction (T1), 5 min after stabilizer application for anastomosis of the left anterior descending coronary artery (T2), the obtuse marginalis branch (T3) and the RCA (T4) and 5 min after sternum closure (T5). RESULTS: There were no significant differences in hemodynamic variables between two groups during all study periods except in RVEF. RVEF was significantly greater at T2 and T5 in Group 1 than in Group 2. It decreased significantly at T4 in Group 1 and at T3 and T4 in Group 2 compared to values at T1. CONCLUSIONS: RVEF significantly decreased at T2 and T5 in group 2 patients. Other variables affecting the RV function such as cardiac output, pulmonary vascular resistance and RV end diastolic volume index showed no differences between the two groups. These findings suggest that the degree of RCA stenosis has contributed to the decrease in RVEF in patients undergoing OPCAB.

Effect of Preoperative Aspirin Use on Postoperative Bleeding and Thromboelastography in Off-Pump Coronary Artery Bypass Operations / 대한마취과학회지

BACKGROUND: Aspirin has been shown to effectively increase survival and reduce morbidity in patients with ischemic heart disease. Continued aspirin use during the preoperative period could increase the postoperative blood loss in patients who have on-pump coronary artery bypass grafting. This study aimed to determine the effect of continued aspirin use before off-pump CABG on intraoperative and postoperative bleeding and coagulation profile in thromboelastography. METHODS: In 43 patients undergoing OPCAB, they were assigned aspirin user (n = 22), who received aspirin until the day of operation or nonaspirin user (n = 21), who discontinued aspirin before 7 days before the surgery. Intraoperative and postoperative bleeding and transfusion requirement were measured. TEG was performed and R, K, alpha angle, maximum amplitude and TEG index was measured at preinduction and at 24 hours after surgery. RESULTS: There were no differences in patient characteristics between aspirin users and nonaspirin users. We found no significant difference between postoperative bleeding and blood product requirements for the two groups. Similarly, we found no significant difference in the coagulation profiles. CONCLUSIONS: The use of aspirin continued preoperatively does not increase intraoperative and postoperative blood loss, and blood product requirement and influence on coagulation profile.

Proper Target Concentration of Fentanyl during Endotracheal Intubation with a CACI (Computer Assisted Continuous Infusion) in Patients Undergoing Coronary Artery Bypass Graft Surgery / 대한마취과학회지

BACKGROUND: The computer-assisted continuous infusion (CACI) system was developed to more rapidly attain and to maintain stable effect-site fentanyl concentrations as compared with the intermittent injection method. The CACI system allows the anesthesiologist to control effect-site fentanyl concentrations during various surgical stimuli during cardiac anesthesia. This system can rapidly control the depth of anesthesia and compensate for the disadvantages of IV anesthesia. Early patient recovery also enables early tracheal extubation, which is an important component of the "fast track" cardiac surgery pathway. In this study, the use of a target-controlled infusion of low-dose propofol was combined with the target-controlled infusion of fentanyl for patients undergoing coronary artery bypass graft surgery. The purpose of this study was to evaluate the proper effect-site concentration of fentanyl for the tracheal intubation of patients undergoing coronary artery bypass graft surgery. METHODS: Fifty patients scheduled for elective coronary artery bypass graft surgery were included, and randomly allocated to group L (effect-site fentanyl concentration = 5 ng/ml, n = 25) or group H (effect-site fentanyl concentration = 7.5 ng/ml, n = 25). Anesthesia was induced and maintained by the computer-controlled infusions of propofol and fentanyl. Hemodynamics and other variables were recorded preinduction, and before and 1 minute after intubation. RESULTS: The two groups were compared with regard to demographic and perioperative data. The two groups were similar demographically, and no significant differences was found in any hemodynamic parameter at any time between the two groups. CONCLUSIONS: Both fentanyl regimens provided stable hemodynamics and adequate anesthesia in patients during endotracheal intubation. It is reasonable to say that the lower dose of fentanyl (5 ng/ml) may be the better choice, because it provides the same level of anesthesia during endotracheal intubation during coronary artery bypass graft surgery.

The Incidence and Severity of Venous Air Embolism Determined by Transesophaseal Echocardiography in Hepatic Resection Using a Cavitron Ultrasonic Surgical Aspirator Dong / 대한마취과학회지

BACKGROUND: A new technique resecting the hepatic parenchyma without inflow occlusion using a Cavitron Ultrasonic Surgical Aspirator (CUSA(R) ) reduces intraoperative blood loss and perioperative morbidity. This study was designed to identify the incidence and severity of venous air embolism (VAE) using transesophaseal echocardiography (TEE) in hepatic resection using CUSA(R) . METHODS: Forty patients undergoing hepatic resection using CUSA(R) of ASA class 1 and 2 were selected. After insertion of an epidural catheter for postoperative analgesia, all patients were anesthetized with sevoflurane in 50% air/O2. After the induction of anesthesia, A TEE probe was inserted into the esophagus. Blood pressure, heart rate, central venous pressure, end tidal CO2, and arterial carbon dioxide tension were recorded after induction, and during and after hepatic resection. During hepatic resection, an anesthesiologist evaluated the degree of VAE by transesophageal echocardiography in the 4-chamber view. RESULTS: The mean time of using CUSA(R) was 65.3 +/- 24.4 minutes. Of 40 patients, 9 had VAE grade I, 14 grade II, 14 grade III, and 3 grade IV. However, no significant difference was observed in hemodynamics or PaCO2 after induction, or during or after hepatic resection. The mean amount of blood loss was 887.0 ml +/- 598.8 ml and the mean transfused amount was 123.1 +/- 351.3 ml. CONCLUSIONS: All patients showed air embolism during hepatic resection with CUSA(R) . Serious complications associated with air embolism would occur in patients with an undiagnosed intracardiac right to left shunt. Therefore, meticulous monitoring by transesophageal echocardiography might be recommended in hepatic resection with CUSA(R) .