The Effect of Preoperative Pulmonary Arterial Pressure and Right Ventricular Function on the Changes in Right Ventricular Function after Mitral Valve Replacement / 대한마취과학회지

BACKGROUND: In patients with mitral valvular disease with pulmonary hypertension (PHT) accompanying right ventricular (RV) dysfunction, mitral valve replacement (MVR) improves RV function and other hemodynamic variables in long term follow-up. However, there are controversies in improvement of RV function in the immediate postoperative period. We compared the RV function immediately after a MVR with a pulmonary artery catheter (PAC) between patients with normal and decreased RV function with PHT preoperatively. METHODS: Twenty nine patients undergoing a MVR were included in the study. The patients (n = 14) with mean pulmonary arterial pressure (PAP) < or = 25 mmHg were assigned to group I and the patients (n = 15) with mean PAP 25 mmHg were assigned to group II. A PAC with rapid response-thermistors which enables us to determine right ventricular ejection fraction (RVEF) was inserted in all patients and hemodynamic variables were measured before and after cardiopulmonary bypass (CPB). RESULTS: After CPB, PAP, pulmonary vascular resistance index (PVRI), and RV end-diastolc volume (RVEDV) were significantly decreased and RVEF was significantly increased in group II compared with group I in which no hemodynamic variables were changed. CONCLUSIONS: A MVR decreased RV afterload and increased RV function more significantly in patients with preoperative PHT accompanying RV dysfunction than in patients with normal PAP preoperatively.

Effects of Clonidine on the Requirements of Dopamine Used as a Concomitant Drug of Amrinone in Coronary Artery Bypass Surgery (CABG) / 대한마취과학회지

BACKGROUND: Clonidine premedication has many beneficial effects in patients undergoing CABG surgery. Amrinone, having the ability to increase cardiac performance without increasing myocardial O2 consumption, is a valuable drug in postoperative management after cardiopulmonary bypass (CPB). The use of amrinone with a catecholamine is also important clinically because the cathecholamines support perfusion pressure and the combined use exerts synergistic or additive effects. We performed this study to examine whether clonidine premedication could change the amount of dopamine used concomitantly with amrinone for management after CPB. METHODS: Nineteen patients for elective CABG were allocated to two groups according to their premedication; a placebo (Group 1, n = 13) or clonidine 4 microgram/kg p.o. (Group 2, n = 6). All patients arrived in the operating room with infusion of isosorbide dinitrate (ID). Anesthesia was performed with standard techniques. Before initiation of CPB, significant lowering of BP or HR was treated with phenylephrine or atropine respectively. Amrinone was given bolus (0.75 mg/kg) and infusion (10 microgram/ kg/min) was begun instead of ID at the release of aortic cross-clamp. Dopamine infusion (3 microgram/kg/min) was started at 35degree C (rectal) and its rate was adjusted for maintaining acceptable hemodynamics. We compared the amount of infused dopamine within 90 mins after CPB between the two groups. We also compared systolic BP, HR and CVP before induction, 10 mins after induction and 60 mins after CPB. RESULTS: Systolic BP and HR before induction and HR 10 mins after induction were significantly lower in Group 2 (P < 0.05), but they were all within normal range. The proportion of patients who needed phenylephrine or atropine before CPB was not significantly different in the two groups. The amount of infused dopamine was significantly larger in Group 2 (P < 0.05). Hemodynamics were acceptable after CPB although HR 60 min after CPB was significantly lower within the normal range in Group 2 (P < 0.05). Weaning time from CPB was not significantly different in the two groups. No significant adverse effect was observed throughout this study. CONCLUSIONS: Clonidine, used as premedication, increases the need of catecholamine which is concomitantly administered with amrinone for weaning from CPB. But this method provides clinically effective result without jeopardizing hemodynamics in CABG.

The Effects of Intravenous Insulin on Hemodynamics and Autonomic Nervous System Activity in Anesthetized Dogs / 대한마취과학회지

BACKGROUND: Even though the cardiovascular actions of insulin were first described shortly after introduction into clinical practice, the precise physiological role and mechanism of insulin-mediated cardiovascular actions are not known. The aim of the present study was to investigate the changes in hemodynamics after an insulin injection and the role of the autonomic nervous system in mediating the responses to insulin. METHODS: Nine mongrel dogs of the male sex, weighing 20 - 26 kg, were studied. Anesthesia was maintained with pentobarbital and vecuronium after the administration of the loading dose. Femoral and pulmonary artery catheters were placed for obtaining blood samples (ABGA, electrolytes, glucose and plasma catecholamines) and measuring hemodynamic variables. Real time power spectral analysis of R-R interval variability was displayed on the color power spectrum every 30 seconds by a simple connection between the EKG monitor and computer via an A/D converter. After control values were obtained, porcine insulin was administrated intravenously as a bolus injection (2 U/kg). Blood glucose and potassium were maintained within physiological range by simultaneous infusion of 50% glucose (2-4 ml/kg/h) and potassium (0.5-1.0 mEq/kg/h). Parameters were measured respectively in 9 steps; 10min before insulin injection (control), 1, 5, 10, 20, 30, 40, 50 and 60min after insulin injection. RESULTS: Heart rate, mean arterial blood pressure and cardiac output increased and systemic vascular resistance decreased significantly after the insulin injection. No significant changes in plasma norepinephrine and epinephrine levels could be detected. Power spectral density of low frequency and ratio oflow and middle frequency power to high frequency power increased significantly 1min after insulin injection but did not increase thereafter. High frequency power remained significantly below the control value after the insulin injection. CONCLUSIONS: Although catecholamine concentration itself did not show a significant change, PSA data reveals that insulin may exert a stimulatory action on the sympathetic nervous system and a depressive action on the parasympathetic nervous system independent of hypoglycemia immediately after an insulin injection and insulin-induced vasodilation is not related to the autonomic nervous system.

Hemodynamic Changes and Clinical Symptoms Resulting from Stellate Ganglion Block / 대한마취과학회지

BACKGROUND: Stellate ganglion block (SGB) is the most common nerve block procedure in pain clinics. To evaluate changes in the hemodynamics and peripheral blood flow on the affected extremity after SGB, SGB was performed unilaterally one at a time on the right and left stellate ganglions by injecting 1% mepivacaine 10 ml without epinephrine in a designated healthy man. METHODS: SGB was repeated 16 times in one subject (right side SGB: 8, left side SGB: 8) by the same clinician. The mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI) and peripheral blood flow were measured in the supine position before (control), and 3, 6, 9, 12, and 15 minutes after SGB using thoracic electrical bioimpedence (Bioz system A-10043, Cardiodynamics, USA), sphygomanometer, and flow meter. RESULTS: The values after SGB including MAP, HR, CI, and SVRI increased slightly compared to the control value. However, peripheral blood flow increased significantly (p < 0.05). The SGB did not affect systematic hemodynamics and the comparison between left and right SGB in hemodynamic changes were not clinically significant. Following SGB, ptosis (100%), nasal stiffness (100%), skin temperature elevation (100%), hoarseness (100%), numbness (81%), dizziness (25%), and swallowing difficulty (25%) were observed. CONCLUSIONS: We concluded that SGB showed to be a hemodynamically safe clinical technique.

The Effect of Spinal Anesthesia for Cesarean Section on Hemodynamics in Patients with Severe Preeclampsia / 대한마취과학회지

BACKGROUND: Epidural anesthesia is thought to be relatively indicated for cesarean section in patients with severe preeclampsia. In contrast, avoidance of spinal anesthesia is recommended, postulating excessive hypotensive risks. In addition, general anesthesia is often avoided in this population because malignant hypertension following tracheal intubation is common and risks for difficult airway management are excessive. METHODS: In this study, we compared hemodynamic changes in patients with severe preeclampsia and normal pregnant women during spinal anesthesia for elective cesarean section. Spinal anesthesia was performed with 10 mg of 0.5% heavy bupivacaine mixed with 25 microgram fentanyl in 18 patients with severe preeclampsia and 17 normal pregnant women. We compared MAP, CI, and SVRI changes before and after spinal anesthesia. RESULTS: MAP responses following induction of spinal anesthesia for elective cesarean section in patients with severe preeclampsia and normal pregnant women showed a statistically significant decrease from 2 min after spinal anesthesia. CI responses following induction of spinal anesthesia in patients with severe preeclampsia showed a statistically significant increase from 8 min after and normal pregnant women also showed a statistically significant increase from 4 min after spinal anesthesia. SVRI responses from induction of spinal anesthesia in patients with severe preeclampsia and normal pregnant women showed a statistically significant decrease from 2 min after spinal anesthesia. Incidence of hypotension before delivery and used total dose of ephedrine during operation were statically insignificant between severe preeclamptic and normal pregnant women. CONCLUSIONS: We conclude that changes of MAP, CI and SVRI following spinal anesthesia for elective cesarean section in the severely preeclamptic and normal pregnant women are clinically similar. We suggest that spinal anesthesia for cesarean section is not contraindicated in the severely preeclamptic patient.

Midazolam/Sufentanil vs Etomidate/Sufentanil for the Induction of Anesthesia in Patients with Cardiac Disease / 대한마취과학회지

BACKGROUND: Induction of general anesthesia in patients with cardiac disease must guarantee hemodynamic stability and should result in a satisfactory anesthetic level. The purpose of this study was to analyze the hemodynamic effects of midazolam/sufentanil in comparison with etomidate/sufentanil used for induction of anesthesia in patients with cardiac disease. METHODS: All the patients (n = 30) in the study were about to undergo cardiac surgery and were divided into the midazolam group (n = 15) and etomidate group (n = 15). The induction dose of midazolam was 0.18 mg/kg, etomidate 0.3 mg/kg, vecuronium 0.15 mg/kg, sufentanil 3 microgram/kg, hemodynamics and oxygenation were recorded in the awake state (pre-induction), and 10 minutes after intubation (post-intubation). RESULTS: The etomidate group had a shorter time of anesthetic induction, and some myoclonic movement (13%) was observed. After intubation, reductions of heart rate (13.8%), mean arterial pressure (18.4%), cardiac index (14.8%), left ventricular stroke work index (9.7 - 38.5%), oxygen delivery index (7.43%), oxygen consumption index (10.3%), and Qs/Qt (25.6%), and an increase in central venous pressure (0 - 50%) were observed in both groups. Decreases in right ventricular stroke work index and mean arterial pressure were observed in the midazolam group, but no change in right ventricular stroke work index and a decrease in mean arterial pressure was observed in the etomidate group. In the midazolam group the values of right ventricular stroke work index and mean arterial pressure were significantly lower than in the etomidate group. The heart rate of the midazolam group in patients with CABG were significantly lower than in the etomidate group. CONCLUSIONS: The results of this study shows that etomidate was found to be as reliable and effective an agent for induction as midazolam.

Comparision of Hemodynamic Changes in Patients Undertaking Hysterectomies under Genernal and Epidural Anesthesia / 대한마취과학회지

BACKGROUND: The purpose of the study was to evaluate the effect of postural change on hemodynamics using thoracic eletrical bioimpedance (TEB) device during general anesthesia with enflurane-N2O-O2 and lumbar epidural anesthesia. The TEB device is safe, reliable and non-invasive way to measure hemodynmic values continuously. METHODS: General anesthesia (twenty patients) was induced by administration of pentotal sodium 5 mg/kg and succinylcholine 1 mg/kg intravenously, and was maintained with 1 vol% of enflurane, N2O-O2 (2 l/min-2 l/min) and vecuronium 0.1 mg/kg. Epidural anesthesia (twenty patients) was performed at the level of L3-4 epidural space using 20 ml of 2% xylocaine mixed with epinephrine (5 microgram/ml). Hemodynamic changes were measured before induction, 1 and 5 minutes after intubation or epidural injection, 1, 5, 10, 20, 30 minutes after head- down tilt and 1, 5, 10 minutes after returning to the supine position. RESULTS: HR and LVSWI were minimaly affected in group E with epidural anesthesia compared to group G with general anesthesia. BP (SBP, DBP, MAP) and SVRI were remarkably increased in group G compared to group E. BP and SVRI showed rapid increse 1 minutes after head-down tilt in group G (p<0.01) and decreased gradually thereafter. SI and CI were decreased significantly in group G compared to group E (p<0.001). SI was unchanged but CI was decreasd significantly after head-down tilt in group E (p<0.05). EDI and ACI showed lower values decreased in general significantly in group G compared to group E (p<0.05). CONCLUSIONS: All hemodynamic changes were more predictable, gradual, less variable, and stable in the group with epidural anesthesia compared to the group with general anesthesia for hysterectomy.

The Effect of General Anesthesia on Hemodynamics during Laparoscopic Hysterectomy / 대한마취과학회지

BACKGROUND: Laparoscopy with peritoneal carbon dioxide insufflation is a standard procedure in many gynecological departments. And more prolonged gynecological laparoscopic operations are being performed in recent years, and a steeper head-down position is required. Despite laparoscopic operations have many advantages, peritoneal insufflation of CO2 to create the pneumoperitoneum necessary for laparoscopy induces intraoperative hemodynamic changes that complicate anesthetic management of laparoscopy.The purpose of this study is to evaluate the effect of general anesthesia on hemodynamics during loparoscopic hysterectomy. METHODS: Twenty six women undergoing laparoscopic hysterectomy were randomly allocated to either a propofol (Group 1, n=13) intravenous anesthesia or a enflurane (Group 2, n=13) anesthesia with fentanyl-N2O/O2-vecuronium. Hemodynamic parameters were measured before induction (T1), 5 min after induction (T2), 5 min after head-down (T3), 5, 10, 15, 20 min after pneumoperitoneum (T4, T5, T6, T7), 5, 10 min after deflation (T8, T9). The MAP, HR, CI, SVRI, SI were measured by transthoracic electrical bioimpedence method and automated blood pressure device. RESULTS: The mean arterial pressure were increased during pneumoperitonem in both groups and heart rate were increased in Group 2. The cardic index were decreased in both groups after induction by 27.4 % in Group 1 and 25.7% in Group 2. The systemic vascular resistanace index were increased in both groups from head-down to after deflation by 68.3% in Group 1, 73.1% in Group 2 maximally. No significant changes of stroke index were observed during surgery in Group 1. CONCLUSIONS: Laproscopy with CO2 insufflation induces significant hemodynamic changes includig increases of MAP, SVR and a reduction of CI. And usual intraoperative hemodynamic monitoring; the blood pressure and heart rate give no information on the reduction in cardic output.

Effects of Inhaled Nitric Oxide on Cardiopulmonary Hemodynamics and Oxygenation during Induced Hypoxemia in Mongrel Dogs / 대한마취과학회지

INTRODUCTION: One-lung ventilation (OLV), as a model for adult respiratory distress syndrome, was performed in 8 mongrel dogs, which were made a little hypoxemic by adjusting inspired fraction of oxygen (FIO2) in order to know the effect of nitric oxide (NO) on cardiopulmonary hemodynamics and oxygenation during OLV in lateral position. METHODS: Double-lumen endobronchial tube was intubated through tracheostomy. OLV was performed in lateral position by turning to the side where Swan-Ganz catheter tip was located. FIO2 was adjusted to set SpO2 around 85~90%. After stabilization, cardiopulmonary hemodynamic variables and various oxygenation-related parameters were measured respectively at 5 steps: 1) OLV, 2) OLV and 20 PPM of NO inhalation, 3) OLV, 4) OLV and 40 PPM of NO inhalation, 5) OLV. NO (titrated in N2 tank at concentration of 800 PPM) was administered through low-pressure inlet of ventilator and diluted by inspiratory fresh gas. FIO2 setting of ventilator was slightly increased during NO administration to compensate for FIO2 decrease due to NO titration gas (N2) mixing. NO and NO2 concentration was monitored at the inspiratory limb of breathing circuit by a electrochemical analyzer. RESULTS: There were no difference about hemodynamic variables such as blood pressure (BP), pulmonary arterial pressure (PAP), heart rate (HR), central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP). Neither were different calculated hemodynamic variables such as systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), pulmonary perfusion pressure (PPP), cardiac index (CI), and right ventricular stroke work index (RVSWI). PaO2/FIO2, AaDO2, and S/T were significantly different between step 3 and step 4. But other oxygenation-related parameters such as O2, O2 flux, and O2 ER extraction ratio were not different. CONCLUSIONS: NO inhalation may have a potential for relieving hypoxemia during OLV of dogs in lateral position.

Sedation and Hemodynamic Stability during Fiberoptic Awake Nasotracheal Intubation: Comparison between Propofol Infusion and Intravenous Boluses of Fentanyl and Midazolam / 대한마취과학회지

BACKGROUND: Crucial to the success of fiberoptic awake tracheal intubation is proper preparation of the patient; this technique will work well in most patients when they are quiet and cooperative and have a larynx nonreactive to physical stimuli. We have attempted to ascertain how well these conditions are achieved with a low-dose infusion of propofol, because of its pharmacological profile. METHODS: Thirty patients, physical status by American Society of Anesthesiologists (A. S. A.) I-II, scheduled for oral and maxillofacial surgery, were randomly assigned to receive either propofol infusion 1 mg kg-1 h-1 preceded by a 1 mg kg-1 bolus (Group P) or intravenous fentanyl 1ug kg-1 and midazolam 0.05 mg kg-1 (Group F). These two groups were compared in terms of hemodynamic profile, sedation score, condition for intubation, coughing and swallowing. RESULTS: There were no statistically significant differences in mean arterial blood pressures according to time between two groups. But in Group F, heart rates were significantly increased in immediately after transtracheal injection of lidocaine, immediately before the fiberoscopy was started, 1, 2 minutes after start of fiberoscopy, compared to Group P (p<0.05). The patients in Group P were more sedated than those in Group F (p<0.05) but there were no significant differences in condition for intubation, reflex of coughing and swallowing, duration of fiberoptic intubation. CONCLUSIONS: We conclude that propofol is useful sedative agent in fiberoptic awake intubation with similar efficacy to midazolam and fentanyl but with more profound sedation and stable hemodynamic profile. These represent significant advantages for severe anxious or hypertensive patients and prolonged procedure of intubation.

Cardiovascular Effects of Pancuronium, Vecuronium and Pipecuronium during High-Dose Fentanyl Anesthesia in Neonates, Infants and Children / 대한마취과학회지

BACKGROUND: High dose fentanyl for cardiac surgery in neonates, infants and children can cause severe bradycardia and chest wall rigidity that result in decreased cardiac output and oxygen desaturation due to fixed stroke volume in pediatric patients. To ameliorate the effects of fentanyl, it is common to administer neuromuscular blocking drugs with wanted cardiovascular side effects. This study was designed to compare the cardiovascular variables and oxygen saturation among different muscular relaxants in high dose fentanyl anesthesia. METHODS: Thirty pediatric cardiac patients were allocated randomly into three muscle relaxant groups treated with 0.2 mg/kg pancuronium (n=10), 0.2 mg/kg vecuronium (n=10) or 0.2 mg/kg pipecuronium (n=10) after receiving an initial bolus dose of 25 g/kg of fentanyl. Changes of heart rate (HR), mean arterial blood pressure (MAP), rate-pressure-product (RPP) and oxygen saturation (SpO2) were observed. The same cardiovascular variables were also observed 1 and 2 minutes after the second bolus dose of 25 g/kg fentanyl and compared to the results among muscle relaxants. RESULTS: HR, MAP and RPP decreased significantly (p<0.05) 1 and 2 minutes after injection of the 1st fentanyl, which returned to levels above the control value after administration of pancuronium, vecuronium or pipecuronium. Among muscle relaxants, pancuronium caused the most rapid and significantly high level compared to the control value in HR and MAP. Next was pipecuronium and then vecuronium. In clinical setting, SpO2 was decreased after the 1st fentanyl injection and increased after the injection of muscle relaxants, but not significant statistically. CONCLUSION: In view of hemodynamic changes, pancuronium is most efficient and rapid in returning the hemodynamic variables that was decreased after high dose fentanyl anesthesia in neonates, infants and children whose cardiac output was dependent on HR due to relatively fixed stroke volume.

Hemodynamic Changes Associated with Uterine Contraction under Obstetric Analgesia / 대한마취과학회지

BACKGROUND: Continuous epidural analgesia is the most widely used technique in obstetric analgesia today. Hemodynamic changes during pregnancy were most remarkable during the uterine contractions of the first stage of labor. The aim of this study was to compare the difference in hemodynamics between two groups with and without obstetric analgesia. METHODS: Twenty healthy parturients were divided into two groups as follows: Group 1; 10 parturients under epidural analgesia, Group 2; 10 parturients without epidural analgesia,and hemodynamic changes were monitored throughout labor. For the purpose of analysis, the course of labor was divided into three categories according to the degree of dilation of the cervix: 4 cm, 4~7 cm and above 7cm. Hemodynamic parameters were obtained during and in-between contractions over the course of labor through transcutaneous impedence cardiography and a noninvasive automatic blood pressure monitor. RESULTS: Heart rate (HR) in Group 2 were more increased than that in Group 1 during uterine contraction. In Group 1, the end-diastolic volume index (EDVI) and stroke volume index (SVI) at 4 cm dilation and SVI at above 7 cm dilation of the cervix were increased during the contraction. In Group 2, HR increased throughout the first stage of delivery and systolic blood pressure (SBP), EDVI at 4~7 cm and above 7 cm dilation and SVI at above 7 cm dilation were increased during contractions. CONCLUSIONS: Our study showed more stability in hemodynamic parameters in parturients under epidural analgesia as compared to those without analgesia. From these results, we conclude that continuous epidural analgesia is very safe to the fetus as well as mother since the technique dose not cause significant hemodynamic change during uterine contractions.