The Effect of Simultaneous and Alternative Cardioplegia Delivery on Right Ventricular Preservation in Patients Undergoing Right Coronary Artery Bypass Graft Surgery / 대한마취과학회지

BACKGROUND: Most surgeons prefer delivering cardioplegia alternatively via the aortic root and coronary sinus in patients undergoing coronary artery bypass graft surgery (CABG). Recently, some surgeons have delivered cardioplegia via the grafted vessel to the obstructed right coronary artery in order to preserve right ventricular function whenever retrograde cardioplegia is delivered. Thus, we have compared the effect on right ventricular preservation between the aforementioned two methods after cardiopulmonary bypass in patients undergoing a right CABG. METHODS: Twenty-eight patients undergoing an elective CABG with significant right coronary artery obstructive disease were allocated into 2 groups. In the alternative cardioplegia delivery group (A-group), cold blood cardioplegia was delivered via the aortic root and coronary sinus alternatively. In the simultaneous cardioplegia delivery group (S-group), cold blood cardioplegia was delivered via the coronary sinus and grafted vessel to the obstructed right coronary artery simultaneously. Hemodynamic measurements were obtained pre-bypass, at pericardial closure and at sternal closure. Data recorded included right ventricular ejection fraction, right ventricular volume index and right and left ventricular hemodynamics. RESULTS: There was no significant difference in the right ventricular ejection fraction between the two groups at pre-bypass, pericardial closure and sternal closure. In both groups, the right ventricular ejection fraction and cardiac index were not decreased, and the left ventricular ejection fraction was higher at pericardial closure than pre-bypass. However, in both groups, there was a decrease in the right andleft ventricular stroke work index and right ventricular stroke volume index at sternal closure. CONCLUSIONS: We have concluded that simultaneous cardioplegia delivery via the coronary sinus and grafted vessel to the obstructed right coronary artery was not superior to the alternative cardioplegia delivery via the aortic root and coronary sinus for preservation of right ventricular function in patients undergoing a right CABG.

A Comparison of Carbon Dioxide Tensions between Arterial Blood and Oxygenator Exhaust Gas during Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Maintenance of adequate concentration of carbon dioxide during hypothermic cardiopulmonary bypass is important in order to improve tissue perfusion by maintaining vasodilatation. This study evaluated the usefulness of the analysis of gas sampled from the exhaust port of a membrane oxygenator in the estimation of carbon dioxide tension in arterial blood (PaCO2). METHODS: One hundred sixty four arterial blood gases were drawn from 45 adult and 30 pediatric cardiac surgical patients undergoing hypothermic cardiopulmonary bypass. Carbon dioxide tensions were measured in the membrane oxygenator exhaust gas (swept gas; PswCO2) using a capnography and in arterial blood using intermittent gas analysis. We compared the PswCO2 with temperature-uncorrected (alpha-stat) and -corrected (pH-stat) PaCO2 during cardiopulmoary bypass. RESULTS: The mean PaCO2 measured with alpha-stat and pH-stat, and PswCO2 obtained in adult patients during hypothermic cardiopulmonary bypass were 29.8 +/- 4.9, 19.5 +/- 4.1 and 22.3 +/- 4.2 mmHg, respectively. In pediatric patients, alpha-stat PaCO2, pH-stat PaCO2 and PswCO2 were 39.7 +/- 7.7, 24.7 +/- 6.2 and 20.3 +/- 6.0 mmHg, respectively. There was a significant positive correlation between PswCO2 and alpha-stat PaCO2 (adult patients: slope = 0.49, r = 0.64, P < 0.001; pediatric patients: slope = 0.53, r = 0.68, P < 0.001) and pH-stat PaCO2 (adult patients: slope = 0.85, r = 0.81, P < 0.001; pediatric patients: slope = 0.73, r = 0.73, P < 0.001). On comparison of subsequent measurements, 3.8% (adult patients) and 11.4% (pediatric patients) of changes in PaCO2 and PswCO2 were in opposite direction. CONCLUSIONS: Our results indicate that in adult and pediatric patients undergoing hypothermic cardiopulmonary bypass PswCO2 can be an indicator of changes in trend of PaCO2.

Is Central to Peripheral Arterial Pressure Gradient Influenced by Cardiac Output and Vasoactive Drugs in Canines Undergoing Cardiopulmonary Bypass? / 대한마취과학회지

BACKGROUND: It has been known that radial arterial pressure sometimes underestimates central pressure after cardiopulmonary bypass (CPB) and status of circulatory volume, vascular tone, hemodilution or rewarming were explained as the major causes of this phenomenon. We evaluated the effects of these variables on blood pressure and flow in radial and femoral arteries in dogs undergoing CPB. METHODS: Both radial and femoral arteries were cannulated for pressure monitoring and the opposite side arteries were exposed for the measurement of blood flow in 9 dogs. Radial arterial pressure (RBP), femoral arterial pressure (FBP), aortic pressure (ABP), radial blood flow (RBF), and femoral blood flow (FBF) were measured before and just after the initiation of CPB. All values were also recorded when pump flow or ABP were changed during hypothermic CPB and after rewarming. RESULTS: Unlike patients with cardiac disease, RBP, FBP and ABP were almost the same and changes in pump flow and vasoactive drugs didn't make any clinically significant pressure difference between RBP and ABP during hypothermic CPB or after rewarming in the normal condition of dogs. RBF was constantly maintained when the ABP increased with phenylephrine or decreased with sodium nitroprusside (SNP). However, FBF markedly increased during SNP infusion. CONCLUSIONS: Cardiac output, vasoactive drugs and even CPB didn't exert any effect on RBP and FBP in dogs with a normal cardiovascular system. Cardiovascular abnormalities and vascular change or hemodynamic instability itself may induce a large discrepancy between RBP and ABP in cardiac patients undergoing CPB.

Paroxysmal Hypertension during Cardiopulmonary Bypass in a Patient with Pheochromocytoma Undergoing Coronary Artery Bypass Grafting / 대한마취과학회지

A 39 year old man suffering from pheochromocytoma and coronay artery obstruction diseases was scheduled for coronary artery bypass graft surgery before an adrenalectomy. General anesthesia was induced with fentanyl and midazolam and maintained with intermittent administration of fentanyl and low concentraion of isoflurane. At 5 minutes after commencement of cardiopulmonary bypass (CPB), the mean arterial pressure suddenly elevated to 150 mmHg. Sodium nitroprusside and labetalol were administered rapidly, however, mean arterial pressure could not be lowered below 100 mmHg. After release of aortic cross clamp, the electrocardiography showed tachycardia (150 beats/min) with wide QRS and systolic arterial pressure elevated to 180 mmHg. Antiarrhythmic drugs, inotropic and antiischemic drugs were administered. Thereafter tachycardia was disappeared and systolic arterial pressure was lowered below 150 mmHg. We observed the paroxysmal hypertension and tachycardia during CPB that is considered to be attributed to the presence of pheochromocytoma. Therefore we suggest that continuous thoracic epidural anesthesia and pulsatile perfusion during CPB could be helpful in a patient with pheochromocytoma undergoing coronary artery bypass grafting.

Comparison of Analytical Methods of Cerebral Oxygenation during CPB: Hypothermia versus Normothermia / 대한마취과학회지

BACKGROUND: Cerebral oxygen saturation during cardiopulmonary bypass (CPB) has been known to affect the postoperative neurological sequelae. In this study, we compared the oxygen saturation determined by cerebral oxymeter (INVOS 5100) or direct internal jugular vein sampling. METHODS: Thirty patients scheduled for elective coronary artery bypass graft surgery were randomly divided into two groups. Group 1 underwent surgery during hypothermia and group 2 underwent surgery during normothermia. The regional oxygen saturation (rSO2) and the juglar venous oxygen saturation (SjvO2) were measured by a spectrophotometer probe attached to the mid-forehead and by a catheter inserted into the left jugular bulb, respectively. RESULTS: In hypothermic group, the SjvO2 tended to increase during CPB but the rSO2 was significantly decreased. After CPB weaning, both the SjvO2 and the rSO2 were returned to control value. In normothermic group, the SjvO2 and the rSO2 were decreased during CPB and there was no difference between two values. No neurological sequelae were seen in both groups. CONCLUSIONS: These results suggest that the rSO2 may not reflect the SjvO2 accurately during hypothermic CPB unlikely to normothermic bypass.

A Comparative Study of Nonpulsatile and Pulsatile Perfusion on Hemodynamics and Renal Function Centered on the patients undergoing coronary artery bypass grafting with cardiopulmonary bypass / 대한마취과학회지

BACKGROUND: It has been widely believed that pulsatile flow was better than nonpulsatile flow. However it remains uncertain whether pulsatile perfusion has shown substantive clinical improvement compared to standard, nonpulsatile perfusion. The purpose of this study was to compare nonpulsatile perfusion with pulsatile perfusion on hemodynamic and renal function during and after cardiopulmonary bypass (CPB) in the patients undergoing coronary artery bypass grafting (CABG). METHODS: Twenty patients undergoing CABG were divided into two groups, nonpulsatile perfusion group (NP) and pulsatile perfusion group (PP). Hemodynamic data was measured at preinduction, postinduction, immediately after aorta cross clamping (ACC on), and 60 minutes after the start of CPB (CPB 60'). Hemodynamic variables included mean arterial pressure (MAP), peripheral vascular resistance (PVR), plasma catecholamine (epinephrine, norepinephrine), and dosage of the vasodilator (sodium nitroprusside). Renal parameters were urine output, and serum BUN and creatinine. They were measured at preCPB, during CPB, postCPB, and POD 1. RESULTS: MAP was significantly higher in NP at CPB 60'. At CPB 60, PVR returned to preinduction level in NP, but was still decreased in PP. The dosage of vasodilator (sodium nitroprusside) infusionwas significantly higher in NP than in PP. In both groups, plasma epinephrines were increased significantly during CPB but there was no difference between the groups. Plasma norepinephrine was significantly higher in NP than in PP during CPB. At postCPB, urine output was higher than preCPB only in PP. At POD 1, serum BUN increased to the preCPB level in NP but was still decreased in PP. After CPB, serum creatinine was decreased significantly in PP. There was no significant difference in renal parameters between both groups. Conclusion: It was suggested that pulsatile perfusion, compared with nonpulsatile perfusion, can attenuate hemodynamic changes by decreasing release of plasma norepinephrine, peripheral vascular resistance, mean arterial pressure and dosage of vasodilator during cardiopulmonary bypass. Pulsatile perfusion didn't show substantive clinical difference of renal outcome in patients without preoperative renal dysfunction.

Anesthesia for Cardiac Surgery in a Patient with Unsuspected Cold Agglutinin Disease / 대한마취과학회지

Cold agglutinins are autoantibodies activated at low temperature to produce red blood cell agglutination and hemolysis. Systemic hypothermia and cold cardioplegia which are employed commonly in modern cardiac operations are a potential danger to patients with the cold agglutinin disease. We report a successful use of a continuous warm retrograde delivery of cardioplegia with systemic hypothemia in a patient with cold agglutinin disease detected incidentally. Hemagglutination was found in the cold (4oC) blood cardioplegic circuit before the delivery of the cardioplegic solution. Hemagglutination was not detected in the mixture of blood and the warm cardioplegic solution (36.5oC). Therefore, cold agglutinin disease was suspected. The patient was only mildly cooled systemically. The coronary system was perfused with a normothemic cardioplegic solution. With this technique, the patient underwent an uneventful mitral valve replacement operation.

Cardiopulmonary Bypass in Patient with Heparin-Induced Thrombocytopenia Employing Recombinant Hirudin / 대한마취과학회지

Heparin-induced thrombocytopenia (HIT) is a heparin-dependent antibody-mediated platelet activating syndrome frequently accompanying thrombocytopenia, thromboembolism. We experienced a case of cardiopulmonary bypass using hirudin, a direct thrombin inhibitor, in a patient with HIT. The patient who showed thrombocytopenia and thrombosis after heparin re-exposure was highly suspected of having HIT. Hirudin was used in this case as an anticoagulating agent during cardiopulmonary bypass (CPB) to prevent serious complications of heparin. Hirudin 0.3 mg/kg was mixed with a priming solution of CPB and a 0.2 mg/kg IV bolus followed by a continuous infusion of hirudin 0.15 mg/kg given for anticoagulation. After CPB, forced diuresis and platelet transfusion was performed and the patient was recovered without complication.

The Effect of Thiopental Sodium, Etomidate and Propofol on Systemic Vascular Resistance and Venous Capacitance during Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: The focus of this study is the effects of thiopental sodium, etomidate and propofol on systemic vascular resistance and venous capacitance during cardiopulmonary bypass with constant pump flow. METHODS: Thirty patients (ASA III) scheduled for open heart surgery were randomly divided into three groups. Anesthesia was induced with thiopental sodium 5 mg/kg, fentanyl 5 microgram/kg and vecuronium 1 mg/kg. CPB was conduced with a membrane oxygenator using non-pulsatile flow and moderate hypothermia. When rectal temperature and pump flow had been stable for 5 min, patients randomly received thiopental sodium 4 mg/kg, etomidate 0.3 mg/kg and propofol 2 mg/kg. Perfusion pressure and pump flow were measured 0, 1, 3, 5, 10, 15, 20 and 30 min after administration. RESULTS: The systemic vascular resistance index (SVRI) decreased to 84.3% of the control values after thiopental sodium 4 mg/kg, to 74.7% of the control after etomidate 0.3 mg/kg and to 79.8% of the control after propofol 2 mg/kg. SVRI returned to control value levels 3 min after the administration of thiopental sodium, 20 min after etomidate, and 5 min after propofol. Thiopental sodium, etomidate and propofol reduced venous reservoir volume 1 min after injection and the reduction was sustained throughout the all period of the cardiopulmonary bypass. CONCLUSIONS: The results indicate that thiopental sodium, etomidate and propofol dilate both resistance and capacitance vessels, but there was no correlation between the two vessels.

Role of Perfusion Pressure in Major Organ Blood Flow during Cardiopulmonary Bypass in Canines / 대한마취과학회지

BACKGROUND: There has been no report about the effects of blood pressure (BP) on the change of blood flow (BF) to major organs when pump flow is maintained during cardiopulmonary bypass (CPB). We evaluated the changes of the BF and oxygen consumption of major organs when BP was controlled by vasopressors or vasodilators during CPB. METHODS: Carotid, femoral, hepatic and renal arteries and veins were exposed and arteries were cannulated for pressure monitoring, except the hepatic artery and arteries on the opposite side were exposed for the measurement of BF in 7 dogs. Temperature was lowered to 30oC after initiation of CPB and phenylephrine or sodium nitroprusside was infused to increase or decrease BP about 30% under the same pump flow. BP and BF were measured before CPB, before the infusion of drugs and when BP was changed by vasoactive drugs. Blood gas analyses were performed from the artery and each vein while the BF was measured. RESULTS: The change of BP didn't affect carotid and renal BF. However, hepatic BF decreased about 50% when BP was reduced and femoral BF changed in the opposite way of BP change. Oxygen consumption of each organ wasn't influenced by BP. CONCLSIONS: When pump flow was constantly maintained, changes in BP redistributed BF to major organs but didn't affect oxygen consumption. The brain and kidney have the ability of autoregulation of BF unlike the liver or legs. Hepatic BF was dependent on perfusion pressure and a decrease in BP by vasodilators during CPB may be not good for the liver.

Beating Heart CABG under Thoracic Epidural Block Combined with Light General Anesthesia in Renal Transplanted Patient / 대한마취과학회지

Beating heart CABG is defined as a CABG without cardiopulmonary bypass (CPB). Therefore there are no complications associated with CPB. So it is possible to extubate simultaneously with the end of the operation, and also it is effective to reduce the ICU time and the cost. Our team performed a beating heart CABG on a patient who had a history of renal transplantation, to avoid the renal complication due to CPB. We chose the thoracic epidural block combined with light general anesthesia as an anesthetic technique. We managed the patient successfully with consistent hemodynamic stability without the need of any drugs to induce bradycardia. We returned the patient to consciousness before extubation and extubated concurrently with the end of the operation. The patient maintained stable hemodynamics throughout the postoperative period, especially during the ICU stay and we controlled the pain via an epidural catheter with morphine and 0.125% bupivacaine for 3 days. The patient stayed in ICU only one day and was mobile on the second postoperative day. The patient was discharged without any complications, especially renal.

The Effect of Acute Normovolemic Hemodilution on Cardiopulmonary Bypass in Coronary Artery Bypass Grafting Surgery / 대한마취과학회지

BACKGROUND: Systemic arterial hypotension is relatively common following initiation of cardiopulmonary bypass (CPB). Decreased blood viscosity is induced by acute normovolemic hemodilution (ANH) and by the use of crystalloid oxygenator prime. The purpose of this paper is to study the effect of ANH on mean arterial pressure, perfusion flow index and PaO2/FiO2 upon initiation of CPB, and on homologous blood usage during CPB in coronary artery bypass grafting (CABG) surgery. METHODS: We reviewed 30 patients constituting an ANH group, and 30 patients in a control group who had undergone CABG surgery within the past 2 years. In the ANH group, 1 or 2 units of fresh autologous whole blood were sequestrated following induction of anesthesia. We compared mean arterial pressure, perfusion flow index, PaO2/FiO2, and hematocrit on the initiation of CPB, and homologous blood usage during and post CPB periods between the groups. RESULTS: Upon initiation of CPB, hematocrit in the ANH group was significantly less than in the control group, but there was no significant difference in mean arterial pressure, perfusion flow index or PaO2/FiO2 between the groups. The use of homologous blood during CPB in the ANH group was not significantly higher than in the control group. CONCLUSIONS: Acute intraoperative normovolemic hemodilution in CABG surgery was safely performed without significant hypotension and increased homologous blood usage during CPB.

A Comparison of the Effects on Postoperative Course of Hypothermic Circulatory Arrest Versus Continuous Cardiopulmonary Bypass in Infants Arterial Switch Operation / 대한마취과학회지

BACKGROUND: Hypothermic circulatory arrest is a widely used support technique during heart surgery in neonate and infants, but the difference in the effects of perfusion methods, total arrest versus continuous flow, on postoperative course has been controversial. METHODS: This study was retrospectively designed to examine the difference in effects of deep hypothermic circulatory arrest or continuous flow perfusion on postoperative courses including mortality and neurologic morbidity after arterial switch operation through chart review. We also examined the relationship between intraoperative data and postoperative outcomes. RESULTS: Of 72 patients, 44 patients (Total Circulatory Arrest (TCA) group; 26 patients had intact ventricular septum, 18 patients had ventricular septal defect) were treated with total arrest, and 28 patients (Continuous Perfusion Flow (CPF) group; 13 patients had intact ventricular septum, and 15 patients had ventricular septal defect) were treated with continuous flow. Hospital course, postoperative hemodynamic profiles, incidence of complications excluding neurology and mortality were not different between two groups. The incidence of neurologic abnormalities was higher two times in TCA group than in CPF group but was not significantly different. CONCLUSIONS: We could not confirm the differences in postoperative outcomes between both techniques, total circulatory arrest and continuous flow perfusion during arterial switch operation in neonates and infants.

The Effects of Perfusion Variables on the Neurologic Sequelae in the Infants Who had Arterial Switch Operation Using Continuous Flow Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Neurologic sequelae of open heart surgery for congenital heart disease were related with preexisting brain lesion as well as intraoperative causes. These causes are microemboli, blood flow, and blood distribution. METHODS: This study was designed to examine neurologic sequelae and postoperative course in patients with arterial switch operation using continuous flow cardiopulmonary bypass through retrospective chart review. RESULTS: Of 22 patients 4 had neurologic sequelae. Cooling rate, extubation time, and duration of ICU admission and hospital admission were statistically different between the patients with neurologic sequelae or not. Patients with neurologic sequelae had more rapid cooling rate and longer duration of intubation, ICU stay, and hospital admission than patients without neurologic sequelae. CONCLUSIONS: Cooling rate (time to lower 1oC body temperature) is the only factor among perfusion variables to affect on neurologic sequelae. Neurologic complications make it longer to wean the mechanical ventilation, and to stay at ICU and hospital.

Pupil Changes during Hypothermic Cardiopulmonary Bypass Under Fentanyl Anesthesia / 대한마취과학회지

BACKGROUND: Central nervous system dysfunction continues to be a major cause of morbidity after aorta and cardiac surgery under cardiopulmonary bypass (CPB). Pupillary reflexes are important component of the neurologic examination. The purpose of this study was to evaluate how the pupil reacts during hypothermic CPB under fentanyl anesthesia and its relation with postoperative neurologic deficits. METHODS: Fourteen patients undergoing ascending aortic dissection or aneurysm repair surgery under profound hypothermic CPB and circulatory arrest were enrolled. Pupil size and light reflex were evaluated at varying stages of CPB and temperatures. Temperatures were measured at different sites of perfusate, nasopharynx and rectum. Postoperatively neurologic assessments were performed to compare with the pupillary signs. RESULTS: Anesthetic induction with fentanyl decreased pupil size to pinpoint. Pupil dilated progressively under hypothermic CPB reaching fully dilated size at profound hypothermia. Rewarming returned the pupil to original size. Nasopharyngeal temperature correlated well with pupil size during cooling and rewarming. Light reflex was absent at any stage or temperature after anesthetic induction. Seven patients showed insignificant anisocoria and two died of other causes than neurologic deficit. One patient who was not in the anisocoria group exhibited delirium. CONCLUSIONS: Profound hypothermic CPB under fentanyl anesthesia dilates the pupil to a maximum size without light reflex overwhelming narcotic effect. Fully dilated pupil does not denote neurologic damage.

The Effect of CO2 on Body Temperatures during Cooling and Rewarming of Cardiopulmonary Bypass / 대한마취과학회지

Background: It is well known that the addition of CO2 gas during cardiopulmonary bypass (CPB) can increase cerebral blood flow (CBF). In this study, we tried to find whether the increase of CBF by CO2 gas could be expressed on the measurement of body temperatures. Methods: This study included 22 adult patients who underwent CPB with moderate hypothermia and were assigned randomly to two groups by adding CO2 gas (CO2 group and Air group). We measured each tympanic (TM), nasopharyngeal (NP), oral, forehead, finger, rectal and CPB arterial line temperatures of CPB circuit for 20 times during cooling in every one minute for 20 minutes and during rewarming every two minutes for 40 minutes. Results: During cooling and rewarming, the TM, NP and oral temperatures changed more rapidly than the rectal and finger temperatures. In TM temperature, as time changed, the percent changes of temperature varied more prominently in the CO2 gas group than in the Air group. The statistical differences were significant especially during 13 minutes to 20 minutes in cooling and 8 minutes to 20 minutes during rewarming. Conclusion: From this data, we can postulate the effect of CO2 gas on CBF indirectly by measuring several sites of body temperatures.

The Effect of Ultrafiltration in Pediatric Open Heart Surgery / 대한마취과학회지

BACKGROUND: Ultrafiltration is a method to reduce capillary leak and the accumulation of extravascular water associated with cardiopulmonary bypass(CPB). There are two techniques of ultrafiltration, conventional and modified techniques. The effect of the former is controversial. The author investigated the effect of ultrafiltration performed in pediatric open heart surgery in our institute. METHODS: The retrospective study was done in 18 children who received surgical correction of congenital heart disease associated with left to right shunt. Eight children undergone ultrafiltration(UF group) were compared with 10 children who did not receive ultrafiltration(non-UF group). Ultrafiltration was performed mainly during rewarming of CPB(conventional UF) with or without modified technique for about 5 minutes immediately after bypass. Hematocrit(Hct), mean arterial pressure(MAP) and platelet count, 24-h blood loss, the amount of transfusion, fluid requirement, time to extubation, duration of ICU stay and the postoperative hospital stay were compared between groups. RESULTS: The volume of ultrafiltrate was 149+/-88 ml and ultrafiltrate/total blood volume(UF/TBV) ratio was 8.6+/-5.3%. The increase of Hct(5.4+/-1.7%) and of MAP(14+/-5.9 mmHg) after rewarming in UF group were significantly greater than 1.5+/-1.7% and 4+/-8.9 mmHg in non-UF group, respectively(p <0.05). There were no significant differences in platelet count, 24-h blood loss, the amount of transfusion, fluid requirement, maximum body temperature, time to extubation, duration of ICU stay and the postoperative hospital stay between groups. CONCLUSIONS: Ultrafiltration performed during open heart surgery in children significantly increases Hct and MAP immediately after ultrafiltration, but does not affect 24-h blood loss, the time to extubation, duration of ICU stay and the postoperative hospital stay.

Total Intravenous Anesthesia with Sufentanil and Midazolam for Open Heart Surgery / 대한마취과학회지

BACKGROUND: This study was conducted to evaluate the hemodynamic effects, the time to arousal and the postoperative recall with the continuous infusion technique of sufentanil and midazolam used for induction and maintenance of anesthesia in patients undergoing open heart surgery. METHODS: Forty patients with good ventricular function undergoing elective open heart surgery were evaluated. They received midazolam 0.1 mg/kg, pancuronium 0.15 mg/kg and sufentanil 2.5 mcg/kg, followed by infusions of midazolam 0.1 mg/kg/hr, pancuronium 0.02 mg/kg/hr and sufentanil 1.5 mcg/kg/hr until the end of operation. We observed the mean arterial pressure, heart rate and central venous pressure before the initiation of cardiopulmonary bypass(CPB) and recorded the time to arousal after the end of operation and asked about awareness of any intraoperative events on the third postoperative day. RESULTS: The mean arterial pressures during prebypass period were lower than preinduction value but there were no severe hypotension with mean arterial pressures less than 60 mmHg. The mean arousal time of eye opening was 119 minutes and there was no postoperative recall case. CONCLUSIONS: The results show that the infusion of sufentanil with midazolam to patients with good ventricular function provides a stable and safe anesthesia hemodynamically and neurologically and a rapid recovery from anesthesia without postoperative recall.

Hematological Differences between Roller Pump and Centrifugal Pump in Cardiopulmonary Bypass / 대한마취과학회지

BACKGROUND: Prolonged extracorporeal circulation entails tremendous threats of red cell lysis, severe bleeding problems due to platelet injury and activation, and endothelial damages by sequestered leukocytes. In consideration of these problems, a new centrifugal pump was developed and tested clinically to evaluate its effectiveness. METHODS: We compared the effects of a centrifugal pump with those of a roller pump on hematological responses during cardiopulmonary bypass (CPB) in 20 coronary artery bypass surgery patients. The patients were divided into two groups of 10 each. The studied parameters included WBC counts, platelet counts, plasma Hb and D-dimer. Blood samples were taken after sternotomy, at 60 min, 120 min and 180 min after CPB start, and at 2 hr after CPB stop. RESULTS: No differences between the groups were found in bypass time, aortic cross clamp time, extracorporeal circulation flow and hematocrit. The centrifugal pump group demonstrated less platelet depletion (p<0.05), hemolysis (plasma Hb, p<0.05) and fibrinolysis (D-dimer, p<0.05). These differences were CPB time dependent and became statistically significant after 120 min bypass. CONCLUSION: We conclude that roller pump still can be safely used for standard cardiac procedures with bypass time less than 120 minutes and the centrifugal pump has significant potential to be safely applied to CPB for long ypass time in order to avoid postperfusion syndrome.

Pulmonary Hemodynamics in Patients with Pulmonary Hypertension Undergoing Repair of Atrial or Ventricular Septal Defect and Mitral Valve Replacement / 대한마취과학회지

BACKGROUND: The mechanisms of pulmonary hypertension(PHT) are usually quite different in acquired disorders of the left side of the heart from those of congenital heart disease. Accordingly, this study was designed to compare pulmonary hemodynamics immediately after cardiopulmonary bypass(CPB) in patients with undergoing repair of atrial(ASD) or ventricular septal defect(VSD) and mitral valve replacement(MVR). METHODS: 49 patients with PHT defined as a resting systolic pulmonary arterial pressure(SPAP) greater than 35 mmHg were studied and were divided preoperatively into two groups; repair of ASD or VSD(Group I, n=18) and MVR(Group II, n=31). Measurements were made after sternotomy and prior to initiation of CPB and upon stabilization following discontinuation of CPB. RESULTS: In group I, SPAP, DPAP and MPAP decreased by 44%, 22% and 35% respectively and pulmonary vascular resistance index(PVRI) decreased by 47% after CPB. In group II, SPAP, DPAP and MPAP revealed 25%, 32% and 29% reduction respectively and PVRI decrease by 39% after CPB. SPAP decreased more significantly after CPB in group I(44% vs 25%, p<0.05). CI increased significantly in group II while decreased in group I. Intraoperative inotropes and vasodilators were used more in group II than in group I(24/31 vs 6/18). CONCLUSIONS: The successful replacement of the valve and patch repair of defect may reduce both PAP and PVRI moderately in patients with PHT.