The Changes in Lung Mechanics before and after the Nuss Operation in Pectus Excavatum Patients / 대한마취과학회지

BACKGROUND: Nuss et al introduced a less invasive method for inserting a stainless steel bar through the small incision on the lateral chest wall into the pectus excavatum. This study was undertaken to assess the effect of the Nuss operation on lung mechanics, CT-Index and hemodynamics. METHODS: Twenty patients (age 4 to 17 years) with severe pectus excavatum underwent the Nuss operation. CT-Index (the internal transverse distance of the thorax/the vertebral-sternal distance at greatest depression) was evaluated before operation. Lung mechanics (dynamic compliance [Cdyn], static compliance [Cstat] and airway resistance [Raw]), hemodynamic changes (heart rate [HR], systolic blood pressure [SBP], and diastolic blood pressure [DBP]), and gas exchange (arterial oxygen tension [PaO2], arterial carbon dioxide tension [PaCO2], pulse oximeter saturation [SPO2] and end-tidal carbon dioxide tension[PETCO2]) were measured before and after the operation. RESULTS: Cdyn and Cstat decreased significantly (P < 0.05), but Raw did not change. PaCO2 and PETCO2 decreased significantly (P < 0.05), and SBP and DBP increased significantly (P < 0.05) postoperatively. CONCLUSIONS: It is concluded that decreased compliance after the Nuss operation may result from reduced thoracic elastance, not to a change of lung parenchyma.

Hemodynamic Changes during Displacement and Epicardial Stabilization of the Beating Heart in Patients Undergoing Off-Pump Coronary Artery Bypass Graft / 대한마취과학회지

BACKGROUND: Coronary artery bypass grafting without cardiopulmonary bypass (Off-Pump Coronary Artery Bypass Grafting, OPCAB) causes significant hemodynamic derangement by displacement of the beating heart. The purpose of this study was to analyze the hemodynamic changes caused in relation to grafted arteries by displacing the heart and stabilizing the coronary arteries in patients undergoing OPCAB. METHODS: Nineteen patients underwent OPCAB using two deep pericardial sutures and tissue stabilizers (Octopus Tissue Stabilization Syetem, Medtronic, USA). The hemodynamic variables were obtained after induction of anesthesia, after deep pericardial sutures, before and after anastomosis of each coronary artery during epicardial stabilizing, after sternal closure, and after postoperative 6 hours and 12 hours in the intensive care unit. RESULTS: The hemodynamic variables were maintained with the Trendelenburg position, volume loading and low dose vasopressors after deep pericardial stay sutures. Displacement of the heart and placement of the stabilizer on all coronary territories except the obtuse marginal artery before anastomosis showed no significant difference in hemodynamics compared with baseline. Positioning for the graft to the obtuse marginal artery decreased cardiac index (1.6+/-0.4 L/min/m2) and stroke index (27.6+/-9.9 L/beat/m2) and increased systemic vascular resistance (2318.9+/-673.7 dyne sec cm(-5)), resulting in hemodynamic compromise (P<0.01). There were no significant hemodynamic and electrocardiographic changes before or after grafting of other coronary arteries but there was a significant increase in cardiac index after postoperative 6 and 12 hours compared with baseline values (P<0.05). CONCLUSIONS: Although the complete revascularization of most coronary arteries is feasible on the beating heart without significant hemodynamic compromise with minimal vasopressor support, the positioning for the graft to the obtuse marginal artery needs special attention because two deep pericardial stay sutures and Octopus tissue stabilizers on the obtuse marginal artery territory induce significant hemodynamic disturbances.

Effects of Lidocaine, Verapamil and Their Mixture on Neuromuscular Blockade / 대한마취과학회지

BACKGROUND: Lidocaine, verapamil or a lidocaine-verapamil mixture was effectively applied for blunting extubation during recovery from anesthesia. However, these drugs can enhance neuromuscular blockade and cardiovascular depression. We investigated the neuromuscular and the cardiovascular effect of lidocaine, verapamil or a lidocaine-verapamil mixture before extubation in the recovery from anesthesia. METHODS: We studied ninety nine healthy adult patients (ASA class I or II), excluding the patients with cardiovascular diseases and with factors affecting neuromuscular function. Induction of anesthesia was performed with thiopental sodium 5 mg/kg and fentanyl 0.1 mg, and maintained with O2-N2O (50%)-enflurane (2%). Supramaximal single twitch stimuli (0.1 Hz) were applied to the ulnar nerve and the twitch response of the adductor pollicis was recorded by the Gould TA 240 recorder via a 2 kg Load Cell Strain Gauge modification. After stabilization of the twitch response, mivacurium (0.16 mg/kg) or vecuronium (0.1 mg/kg) was administered intravenously and endotracheal intubation was performed. Twitch heights were spontaneously recovered without a reversal agent from the neuromuscular blockade as a spontaneous group. Pyridostigmine 10 mg and glycopyrrolate 0.2 mg were administered intravenously around the time of 10% recovery of baseline twitch height as a reversal recovery group. At the time of 100% recovery of twitch height, train of four (TOF) stimuli was applied and then lidocaine, verapamil or a lidocaine-verapamil mixture was administered intravenously in both groups. Maximum depression of twitch height and the TOF ratio at this point, recovery index (RI) measured, and mean arterial pressure and pulse rates were measured before and at 2, 5, 10, 20 and 30 min. after the lidocaine-verapamil mixture administration. RESULTS: Twitch heights were depressed slightly after lidocaine, verapamil or a lidocaine-verapamil mixture administration; however, there were no significant differences to compare with the control. TOFratios were unchanged after lidocaine, verapamil or lidocaine-verapamil administration compared at the 100% twitch height recovery. RI indices were not significant between groups in reversal recovery or in spontaneous recovery. Mean arterial pressure was reduced significantly until 20 min after a lidocaine-verapamil mixture administration, pulse rates were increased at 2 min only after a lidocaine- verapamil mixture administration. CONCLUSIONS: Twitch height and TOF ratios were not affected by clinical doses of lidocaine, verapamil or a lidocaine-verapamil mixture. However, mean arterial pressure and pulse rates were changed significantly by a lidocaine-verapamil mixture.

Changes of Vital Signs, Expired Volume and Maximal Pressure by Mode of Ventilation during a Nuss Operation in Patients with Pectus Excavatum / 대한마취과학회지

BACKGROUND: This study was undertaken in order to investigate any cardiopulmonary changes caused by the surgical procedure during a Nuss operation in patients with pectus excavatum. METHODS: Thirty patients undergoing the Nuss operation were divided into two groups. The patients were randomly assigned to either Group-V (n = 15) which volume controlled ventilation was applied, or to Group-P (n = 15) where pressure controlled ventilation was applied. Mechanical ventilation provided a tidal volume to be set at approximately 10 ml/kg and a frequency set to keep ETCO2 in range, between 32 mmHg and 38 mmHg. During the surgical procedure, we recorded expired volume (VE) and inspired maximal pressure (Pmax) changes according to the ventilator mode, and then also recorded changes in vital signs. RESULTS: Heart rate and blood pressure had no significant changes in either groups. In Group-V, during rotation of the metal bar, there was a significant decrease in expired volume (P< 0.001), changes of inspired maximal pressure gradually increased with the operation (P< 0.001). In Group-P, rotation of the metal bar caused a significant decrease in expired volume (P< 0.001). CONCLUSIONS: During the Nuss operation, there should be careful observation of changes in the vital signs, expired volume and maximal pressure during insertion and rotation of the metal bar.

Aortic Root Remodeling Procedure in Marfan Syndrome associated with Aortic Dissection: Yacoub-David Technique / 대한흉부외과학회지

We operated on a Marfan patient who had Stanford type A acute aortic dissection, aortic root aneurysm, and aortic regurgitation. The Yacoub-David aortic root remodeling procedure which preserves native aortic valve and replaces all three aortic sinuses and ascending aorta by a Dacron graft, was applied for this patient. A 24mm Hemashield graft was designed to three tongues at the aortic root end to meet the shape of the Valsalva sinuses. The patient recovered from the procedure uneventfully and there was no aortic regurgitation postoperatively.

Comparison of Arterial and End-Tidal CO2 Tension by Position and Time Changes during Hip Replacement Arthroplasty in Elderly Patients / 대한마취과학회지

BACKGROUND: Hip replacement arthroplasty (HRA) is highly traumatic and performed in a lateral position for several hours and dead-space ventilation may increase. So, the difference between arterial and end-tidal PCO2 was investigated depending on the changes in the patient's posture during HRA in elderly patients. METHODS: Forty-three patients scheduled for a HRA were divided into two groups; Adult Group (n = 21, A-Group) and Elderly Group (n = 22, E-Group). Mean arterial pressure (MAP), heart rate (HR), PaO2, PaCO2, and end-tidal carbon dioxide tension (P(ET)CO2) were simultaneously measured at 10 min after anesthesia in a supine position (S[10]), at 30 min intervals from 30 min (L[30]) to 180 min (L[180]) in a lateral position and at 10 min in a supine position after the end of surgery (ES[10]) in both groups. The PaCO2-P(ET)CO2 gradient (P[a-ET]CO2) and dead space ventilation (Vd/ Vt) were calculated. RESULTS: At S(10), P(a-ET)CO2 in the A- and E-Groups was 7.0 +/- 5.0 and 7.2 +/- 3.3 mmHg respectively. From L(30) to ES(10), the P(a-ET)CO2 and the ratio of Vd/Vt in both groups increased significantly and progressively (P < 0.05 vs the control value) and the slope in the E-Group rose two times as compared to that in the A-Group. The correlation coefficient between P(a)CO2 and P(ET)CO2 was very significant from S(10) to L(90) and ES(10) in the A-Group, and from S(10) to L (60) in the E-Group (P < 0.01). CONCLUSIONS: For maintaining adequate ventilation of the elderly patient during HRA, PaCO2 should be measured intermittently along with the position changes after anesthesia in addition to the constant monitoring of PETCO2.

Comparative Study of Pharmacokinetics in the Onset and Offset of Mivacurium and Other Muscle Relaxants / 대한마취과학회지

BACKGROUND: The purpose of this study was to evaluate mivacurium in the pharmacokinetics of onset and offset. METHODS: In 127 adult patients of ASA physical status I or II without any factors involving the neuromuscular function under general anesthesia, onset time (lag and manifest time) and clinical duration were measured after bolus or divided doses of ED95 x 2 of succinylcholine (SCC), rocuronium (ROC), atracurium (ATR), mivacurium (MIV), pancuronium (PAN) or vecuronium (VEC). Recovery time was defined as the recovery index and total duration measured after subsequent ED95 of MIV at 25% recovery of control twitch height from neuromuscular block induced by ED95 x 2 of ATR, MIV, PAN or VEC. Plasma cholinesterase (PChE) levels were measured following PAN or ATR. RESULTS: Onset time was faster with SCC and ROC, the low potency drugs, than with ATR, MIV, PAN or VEC, the high potent drugs. Manifest time was shorter in low potency drugs but longer in high potency drugs than lag time after bolus or divided doses of muscle relaxants given. Divided doses of various drugs induced a shortened onset time, but the patterns of relationship between lag and manifest time associated with drug potency did not alter. The recovery times with administered MIV were slowest after PAN pretreatment, and fastest after MIV pretreatment. PChE levels decreased significantly from 3 min to over 180 min after PAN administeration but not ATR. CONCLUSIONS: The onset time of MIV was not improved due to high drug potency as other nondepolarizing neuromuscular blockers. However, in spite of high potency, the recovery time of MIV was faster than other drugs. This results may be depend upon PChE activity rather than drug potency. Additionally, the prolonged recovery of MIV was not only under the influence of low PChE activity but also other some factors such as: the first relaxants administered before MIV dominated the neuromuscular block so that the duration of MIV given subsequently changed to resemble that of the first. The longer elimination half-life of the underlying relaxant prolonged the effects of subsequentshorter acting MIV. Structural similarities or dis-similarities between the interacting MIV and other drugs may have effects more potent in dis-similarity than in similarity.

Analgesic Effect of Epidural Clonidine after Cesarean Section / 대한마취과학회지

BACKGROUND: The importance of the intrinsic analgesic properties of the alpha 2-agonist is difficult to establish, but many studies have shown the beneficial effect of epidural clonidine in postoperative pain management. The authors examined the analgesic effect of clonidine, a preferential alpha 2-adrenergic agonist, upon hemodynamics, and side effects during the post-operative period in patients undergoing Cesarean section. METHODS: Sixty healthy parturients undergoing Cesarean section with general anesthesia were divided into two groups as follows: 1) Epidural Morphine group: An initial dose of morphine 3 mg diluted with 10 ml of 0.125% bupivacaine was injected epidurally at time of the peritoneal closure, followed by a continuous epidural infusion of morphine 7 mg and 100 ml of normal saline for the postoperative 2 days. 2) Epidural Clonidine group: An initial dose of clonidine 150 microgram diluted with 10 ml of 0.125% bupivacaine was injected epidurally at time of the peritoneal closure, followed by a continuous epidural infusion of clonidine 1800 microgram and 100 ml of normal saline for the postoperative 2 days. Postoperative analgesia was assessed by recording the VAS (Visual Analogue Scale), PHS (Prince Henry Score) at postoperative 1, 2, 3, 6, 12, 24, and 48 hours. Blood pressure, heart rate, sedation, and side effects were also recorded. RESULTS: There were no statistically significant differences in the VAS and hemodynamic changes between the two groups, but the epidural clonidine reduced the PHS significantly at 1, 2, 3 postoperative hours (P < 0.05). There were less side effects in the cases of epidural clonidine as compared with epidural morphine. CONCLUSION: In comparison to epidural morphine, epidural clonidine produces a similar degree of analgesia but less side effects.

Effects of Etomidate, Propofol and Thiopental Sodium on Intraocular Pressure during the Induction of Anesthesia / 대한마취과학회지

BACKGROUND: During ophthalmologic surgery, a variety of anesthetic induction techniques are used in an attempt to prevent the rise of intraocular pressure (IOP). This study compared the effects of etomidate, a new intravenous anesthetic agent, on the changes in IOP with those of thiopental sodium and propofol. METHODS: Forty-five patients were randomly allocated and divided into three groups to be injected intravenously with etomidate 0.2-0.3 mg/kg (E-group, n = 15), propofol 2-3 mg/kg (P-group, n = 15) or thiopental sodium 4-5 mg/kg (T-group, n = 15). Systolic arterial pressure (SAP), heart rate (HR) and intraocular pressure (IOP) were measured at 1, 2 and 3 minutes after the administration of the induction agents. During the induction of anesthesia, the incidence of IV injection pain, myoclonus, hiccup and a decrease in SAP of more than 30% were investigated. RESULTS: At 1, 2 and 3 min following the induction of anesthesia, the SAP in the P-Group decreased significantly more than that in the other two groups (P < 0.05). After the induction, heart rate in the T-Group increased significantly more than that in the other two groups (P < 0.05). The three intravenous agents induced a significant decrease in IOP after an injection (P < 0.05). Comparing the three groups, the IOP in the E- and P-Group decreased significantly more than that in the T-Group (P < 0.05). CONCLUSIONS: Etomidate may be used as a choice of intravenous induction agent to reduce intraocular pressure in ophthalmologic operations especially in an emergency situation, geriatric and hypovolemic patients.

The Correlation between Perception and Nociception Thresholds by Selected Current Stimuli in Adults / 대한마취과학회지

BACKGROUND: This study was designed to investigate the correlation between pain and non-pain sensation of the cutaneous nociceptors in healthy adults use 250 Hz and 5 Hz evoking neuroselective sinusoidal current to A delta and C-fiber separately. METHODS: Fifty healthy adult volunteers who have no history of neurological illness were examined. Twenty-five of them were male, and twenty-five were female. Their ages ranged from 20 to 46 years, with a mean equal to 29.5 years old. The thresholds for both current perception and nociceptive perception were measured bilaterally in volar aspect of wrist using a Neurometer CPT/C (Quantitative Sensory Nerve Testing Device). The manual mode for current perception threshold and the staircase method for nociceptive current perception threshold was performed individually. RESULTS: The mean values of the threshold for perception evoked by 250 Hz were 0.30 mA in left and 0.31 mA in right, 0.17 mA in left and 0.14 mA in right at 5 Hz respectively. The mean values of the nociception threshold were 0.52 mA in both site at 250 Hz and from 0.35 mA to 0.32 mA at 5 Hz (Table 1). There were no differences between left and right wrist (Fig. 1). Also a significant positive correlation between current perception and nociception thresholds was found (p<0.05) (Fig. 2, 3). There appeared to be different between genders in perception threshold evoked by 250 Hz and nociception threshold evoked by 5 Hz in left (p<0.05) (Table 2). CONCLUSIONS: There exists a meaningful correlation between both sensations of non-pain and pain perception thresholds obtained from all subjects. The measurement of the current perception threshold is considered to be a unique and valuable resource in evaluation of patient with neurologic condition, as well as in serial evaluation of patient to assess the outcome of therapeutic intervention.

Incidence of Cesarean Section Following a Continuous Lumbar Epidural Analgesia for Labor Pain / 대한마취과학회지

BACKGROUND: This retrospective study was subjected to evaluate a causal relation in the incidences of Cesarean section with or without epidural analgesia during labor. METHODS: All of the subjects was divided into two groups which consisted of 394 cases wanted epidural analgesia as Epidural group and 2938 cases unwanted it as Non-epidural group. Continuous lumbar epidural analgesia was performed at L3-4 interspace with catheter advancing 3 cm cephalad when cervix was dilated to at least 3~5 cm and then patient was placed lateral decubitus or sitting posture. 0.125% bupivacaine 10 ml was injected initially via the epidural catheter and then followed by a mixture (10 ml) of bupivacaine 16.7 mg and fentanyl 16.7 microgram hourly to be infused continuously. The data were analysed using Pearson's x2 test with p<0.05 taken as a significant difference. RESULTS: The incidence of normal spontaneous vaginal delivery and Cesarean section, the cause of alteration to Cesarean section, and gestational frequency followed by Cesarean section rate showed no significant difference between two groups. The occurrence of neonate below 7 points of Apgar score at one and five minute after Cesarean section was rather more in Non-epidural group (p<0.05) than that in Epidural group. CONCLUSION: It is concluded that the continuous lumbar epidural analgesia with the dose of bupivacaine and fentanyl as mentioned above does not affect to Cesarean section rate during labor, which provides safe and effective for labor pain control.