Radiation safety: a focus on lead aprons and thyroid shields in interventional pain management

C-arm fluoroscopy is useful equipment in interventional pain management because it helps to guide correct needle targeting for the accurate injection and drug delivery. However, due to increased use of C-arm fluoroscopy in various pain procedures, the risk of radiation exposure is a significant concern for pain physicians. The harmful biological effects of ionizing radiation on the human body are well known. It is therefore necessary to strive to reduce radiation exposure. Lead aprons with thyroid shields are the most fundamental radiation protective devices for interventional procedures, and are very effective. However, the operator's radiation safety cannot be guaranteed because pain physicians seem to lack sufficient interest, knowledge, and awareness about radiation safety. Also, inappropriate care and use of radiation protective devices may result in a higher risk of radiation exposure. The purpose of this article was to review the literature on radiation safety with a focus on lead aprons and thyroid shields and present recommendations related to those devices during C-arm fluoroscopic-guided interventions by pain physicians.

Corrigendum: Effect of muscle relaxation on the oxygenation of human skeletal muscle: a prospective in-vivo experiment using an isolated forearm technique / 대한마취과학회지

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Effect of muscle relaxation on the oxygenation of human skeletal muscle: a prospective in-vivo experiment using an isolated forearm technique / 대한마취과학회지

BACKGROUND: Total oxygen consumption has been found to be reduced under deep neuromuscular blockade due to a lower rate of metabolism of skeletal muscles. However, the magnitude of this effect in individual muscles has not been investigated. Thus the aim of this study was to compare the oxygenation of paralyzed versus non-paralyzed forearm muscle under tourniquet-provoked ischemia. METHODS: After ethics approval and written informed consent, 30 patients scheduled for elective hand and wrist surgery were included. Ischemia was provoked by inflation of bilateral upper arm tourniquets and muscle relaxation was achieved via intravenous administration of rocuronium 0.9 mg/kg. Bilateral tourniquets were applied to both upper arms before induction of anesthesia and near infrared spectrometry (NIRS) electrodes applied on both forearms. Muscular ischemia in an isolated (= non-paralyzed, NP) as well as a paralyzed forearm (P) was created by sequential inflation of both tourniquets before and after intravenous administration of rocuronium. Muscle oxygen saturations (SmO2) of NIRS in both forearms and their changes were determined and compared. RESULTS: Data of 30 patients (15 male, 15 female; 41.8 +/- 14.7 years) were analyzed. The speed of SmO2 decrease (50% decrease of SmO2 from baseline (median [percentiles]: NP 210 s [180/480s] vs. P 180 [180/300]) as well as the maximum decrease in SmO2 (minimum SmO2 in % (median [percentiles]: NP 20 [19/24] vs. P 21 [19/28]) were not significantly affected by neuromuscular paralysis. CONCLUSIONS: No significant effect of muscle relaxation on NIRS-assessed muscle oxygenation under tourniquet-induced ischemia was found in human forearm muscles.

Comparison of Analgesic Efficacy between Single Interscalene Block Combined with a Continuous Intra-bursal Infusion of Ropivacaine and Continuous Interscalene Block after Arthroscopic Rotator Cuff Repair

BACKGROUND: This study evaluated the effectiveness of a continuous interscalene block (CISB) by comparing it with that of a single interscalene block combined with a continuous intra-bursal infusion of ropivacaine (ISB-IB) after arthroscopic rotator cuff repair. METHODS: Patients who had undergone CISB (CISB group; n = 25) were compared with those who had undergone ISB-IB (ISB-IB group; n = 25) for more than 48 hours after surgery. The visual analog scale (VAS) for pain, motor and/or sensory deficit, supplementary analgesics and adverse effects were recorded. RESULTS: There were no significant differences between the postoperative VAS of the CISB and ISB-IB groups, except at 1 hour after surgery. Their supplementary analgesics of the two groups were similar. Transient motor weakness (52%) and sensory disturbance (40%) of the affected arm were observed in patients in the CISB group. The catheters came out accidentally in 22% of the CISB group but in only 4% of the ISB-IB group. CONCLUSIONS: ISB-IB provides similar analgesia to CISB. However, the ISB-IB group had a lower incidence of neurological deficits and better catheter retention.

Comparison of the Efficacy and Safety of Two Different Concentrations (0.2% & 0.25%) Levobupivacaine Infused Epidurally as Analgesia for Elderly Patients Undergoing Abdominal Surgery

BACKGROUND: Levobupivacaine appears attractive as epidural analgesia because it is less cardio- and neurotoxic than its racemic mixture. This study evaluated the efficacy and safety of two different concentrations of levobupivacaine infused epidurally as analgesia for elderly patients undergoing abdominal surgery. METHODS: This prospective study evaluated the quality of postoperative analgesia, the six graded physical activity score, the time to the first passage of flatus, the time to the first oral intake of clear fluid, and the postoperative hospital stay in patients who received a continuous thoracic epidural infusion of levobupivacaine at two different concentrations over a 48 hour period: Group 0.2% (n = 15) or Group 0.25% (n = 15). The incidence of side effects, such as motor block, hypotension, and bradycardia, was also assessed. RESULTS: There were no differences with regard to the verbal numerical rating scale at rest and cough, the total consumption of rescue analgesia, the incidence of side effects, and the overall satisfaction. The physical activity scores at postoperative 24 and 48 hours were similar in both groups. However, the time to the first passage of flatus and time to the first oral intake of clear fluid was significantly faster in Group 0.25% than in Group 0.2% (P < 0.05). CONCLUSIONS: The continuous thoracic epidural infusion of levobupivacaine in elderly patients after abdominal surgery at both 0.2% and 0.25% provides a similar quality of analgesia without any significant motor block. However, increasing the concentration to 0.25% provides a more rapid return of the bowel function but does not shorten the postoperative hospital stay.

Anesthetic Management of Embolization for a Cerebral Aneurysm in Patient with Portal-systemic Encephalopathy: A case report / 대한마취과학회지

The clinical syndrome of hyperammonemic encephalopathy is often encountered in the context of decompensated liver disease. Although it is rare in patients without hepatic disease, non-hepatic causes cannot be excluded. Anesthesiologists should be careful in choosing the anesthetic agent and perioperative management for hyperammonemic patients in order to avoid acute hyperammonemia and encephalopathy. We report successful general anesthesia during GDC (Guglielmi detachable coil) embolization for a large unruptured aneurysm in the right distal internal carotid artery in a female patient with hyperammonemic encephalopathy that was caused by a portal-systemic shunt.

Influence of Unmeasured Anions Identified by Stewart Principle on the Length of Postoperative Hospital Stay / 대한구급학회지

BACKGROUND: Calculation of the base excess (BE) and the anion gap (AG) is commonly used to identify the presence and to analyze the cause of metabolic acidosis in critically ill patients. However, the calculation of BE assumes normal water content, electrolytes, and albumin, changes in these values will change the calculated BE. Calculation of the AG does not control for changes in albumin and cannot distinguish plasma concentration changes of negatively charged protein (albumin) from that of other anions. Based on Stewart's physicochemical principles, Gilfix et al developed equations to calculate the BE caused by unmeasured anions (BEua) taking into account changes in free water, chloride, albumin, and PCO2 that theoretically should reflect metabolic changes better than the less complete biochemical measurements. This study was designed to evaluate the influence of BEua and other variables on the length of postoperative hospital stay. METHODS: The data from 100 consecutive patients were collected prospectively in patients who underwent intra-abdominal operations under general anesthesia and admitted to the adult intensive care unit. All samples were routine samples taken from arterial lines postoperatively and analyzed for arterial blood gas, plasma electrolytes, inorganic phosphates and albumin concentrations. BEua was calculated from the equations developed by Gilfix et al. We also calculated AGNa, K (Na++K+-Cl--HCO3-) and AGNa (Na+-Cl--HCO3-). Correlations between the length of postoperative hospital stay and these variables were studied using linear regression analysis. RESULTS: BEua and BE were significantly correlated with the length of ICU stay (r=0.295, p<0.01 and r=0.249, p<0.05). Neither AGNa, K nor AGNa was correlated with the length of ICU stay. Significant correlation was observed between the length of postoperative hospital stay and BEua (r=0.316, p<0.01), BE (r=0.288, p<0.01), AGNa, K (r=0.284, p<0.01), and AGNa (r=0.263, p<0.05). CONCLUSIONS: In this study BEua was significantly correlated with the length of ICU stay and postoperative hospital stay compared with other variables. This finding suggests that BEua may be used as a more reliable predictor of outcome in ICU patients.

A Comparison of Manual and Mechanical Ventilation in Terms of the Adequacy of Ventilation during Intrahospital Transport of Neurosurgical Patients in the Immediate Postoperative Period / 대한마취과학회지

BACKGROUND: Ambu-bags and portable ventilators can provide intubated patients with ventilation during intrahospital transport, where it is desirable to maintain normocarbia. This study was designed to compare the amount of variation in ventilation that occur during the intrahospital transport of neurosurgical patients ventilated either manually or with a portable ventilator. METHODS: 40 patients were randomized to receive either manual ventilation (Group A, n = 20) during transport or ventilation by a portable ventilator (Group P, n = 20) during the immediate postoperative period. In group A, an adult laerdal resuscitator bag with a reservoir bag (2,600 ml) was used and oxygen (15 L/min) was supplied from a portable oxygen tank. In group P, a portable ventilator was set to controlled mechanical ventilation or synchronized intermittent mandatory ventilation mode, 8.5-10 ml/kg of tidal volume, 1:2 of inspiratory to expiratory ratio, and 100% oxygen concentration. Respiratory rates were adjusted to maintain normocarbia. Hemodynamic parameters were recorded before and during transport. Arterial blood gas levels were also obtained before and during transport. RESULTS: PaCO2 during transport was significantly lower in Group A than in Group P (P < 0.05). Manually ventilated patients showed greater deviations from normocarbia (35-45 mmHg) than mechanically ventilated patients (P < 0.01). PaO2 during transport was no different in the two groups. Blood pressure and heart rates during transport increased significantly in both groups versus before transport (P < 0.01). CONCLUSIONS: The use of a portable ventilator can effectively maintain normocarbia and produce the stable ventilatory pattern during the intrahospital transport of neurosurgical patients during immediate postoperative period.

Sedation with Propofol-Midazolam Combination versus Propofol alone during Spinal Anesthesia: Prospective, Randomized Study / 대한마취과학회지

BACKGROUND: Propofol can produce a dose-dependent reduction in blood pressure by providing titratable sedation and rapid recovery. It has been reported that a combination of midazolam and propofol resulted in the significant reduction in the total dose of propofol needed. It was hypothesized that the addition of low-dose midazolam to propofol may provide sufficient sedation without compromising the hemodynamic stability. METHODS: A total of 40 consecutive patients were randomly assigned to one of two groups (n = 20 each). Group M-P received a bolus of 0.02 mg/kg of midazolam, followed by a propofol infusion with a fixed target concentration of 1.0microgram/ml. Group P received only a propofol infusion with an initial target plasma concentration of 2.5microgram/ml. Subsequent titration of the infusion rates in Group P or the additional midazolam boluses in Group M-P were made in order to maintain a predetermined sedation level. RESULTS: In Group P, a mean dose of 5.4 +/- 0.7 mg/kg/h propofol was used compared with 2.7 +/- 0.5 mg/kg/h in Group M-P (P<0.0001, plus additional 2.96 +/- 1.8 mg of midazolam). Ephedrine was administered to 15 patients in Group M-P and 17 patients in Group P. Recovery was significantly fast (Group P, 6.8 +/- 2.9 min vs. Group M-P, 9.8 +/- 4.4 min, P<0.05). CONCLUSIONS: Sedation with propofol plus midazolam requires a lower total dose of propofol compared with propofol alone but has no superior hemodynamic stability. A further study using younger patients and combinations of different doses of each drug will be needed.

Factors Influencing Postoperative Urinary Retention in Female Patients Undergoing Total Knee Replacements / 대한마취과학회지

BACKGROUND: Postoperative urinary retention is defined as the inability to void with a full bladder during the postoperative period. It affects both sexes in all ages following all types of operation, including patients who previously had no micturition problems. We investigated the incidence and risk factors of urinary retention following long spinal anesthesia for total knee replacement. METHODS: We retrospectively studied a number of factors that may be associated with urinary retention in 98 women. The outcome variable of logistic regression models are urinary retention and severe urinary retention. The potential explanatory variables are age, height, weight, history of hypertension, DM and abnormal urology, heavy bupivacaine dose, types of patient-controlled analgesia, time to regression of spinal block to sacral segments (Tregression), amount of fluid and duration of surgery. We constructed a multiple linear regression model of the time from subarachnoid injection to spontaneous voiding (Tvoiding) in relation to above variables. RESULTS: The overall rate of urinary retention and severe retention were 57.1% and 30.6%. Tregression was identified as significant explanator of an increased probability for urinary retention (P = 0.002), Tregression and DM for severe urinary retention (P <0.001, P = 0.054). In the multiple linear regression model, three variables - Tregression, age, abnormal urological history were identified to have significant t-values (3.902, 3.107, 2.284) with Tvoiding (P <0.001, P = 0.003, P = 0.025). CONCLUSION: Old age, DM, abnormal urological history, delayed recovery of spinal anesthesia are risk factors to urinary retention or delayed spontaneous voiding.

Perioperative Coagulation Responses to Heparin and Dextran Following Arterial Bypass in Patients with Arteriosclerosis Obliterans / 대한마취과학회지

BACKGROUND: The administration of low dose heparin and dextran therapy in patients with arterial bypass surgery is thought to prevent thrombosis and graft occlusion. The purpose of this study was to evaluate the effectiveness of low dose heparin and dextran in atherosclerosis patients presenting hypercoagulability. METHODS: Whole blood coagulation was evaluated using thrombelastography and standard coagulation testing before and a day after surgery in nine atherosclerotic patients and nine control patients. Heparin 5000 U and dextran 500 ml were administrated in atherosclerotic patients during their operations. RESULTS: Atherosclerotic patients showed higher maximal amplitude compared to the control patients during preoperative thrombelastography. After surgery atherosclerotic patients revealed no significant change, but the control group became more hypercoagulable in status compared to the preoperative period. CONCLUSIONS: Intravenous heparin and dextran prevented postoperative change to a more hypercoagulable state than the preoperative status in atherosclerotic patients undergoing arterial bypass surgery.

Intravenous Clonidine Prolongs Spinal Anesthesia after Hyperbaric Bupivacaine / 대한마취과학회지

BACKGROUND: The prolonging effects of oral clonidine premedication on spinal anesthesia are known. We hypothesized that intravenous clonidine might have the same effect even if administered after an intrathecal local anesthetics injection. METHODS: To assess the prolonging effect of intravenous clonidine on spinal anesthesia, we designed a double-blinded, placebo-controlled, prospective study. Patients scheduled for orthopedic surgery were studied. All patients received 12 mg of hyperbaric bupivacaine intrathecally and were allocated to three groups. Group 1 (n = 26) was the control. Group 2 (n = 26) and Group 3 (n = 26) received 3mug/kg intravenous clonidine at the same time and 50 minutes after intrathecal hyperbaric bupivacaine injection. Sensory block was evaluated by pinprick and the duration was defined as the time needed for regression to L1 dermatome. Duration of motor blockade was defined as the time needed for recovery of knee flexion. RESULTS: The duration of sensory block was longer in Group 2 (196+/-42 minutes) and 3 (179+/-41 minutes) than Group 1 (125+/-25 minutes). The Duration of motor blockade was longer in Group 2 (153+/-26 minutes) than Group 1 (131+/-29 minutes). The lowest heart rate and mean blood pressure were not different among the groups. CONCLUSIONS: Intravenous clonidine after an intrathecal hyperbaric bupivacaine injection prolonged spinal anesthesia without added complications.

A Study on the Monitoring of Bupivacaine-induced Cardiac Depression in Dogs: A Comparison between Continuous Mixed Venous Oxygen Saturation and Mean Arterial Blood Pressure / 대한마취과학회지

BACKGROUND: Bupivacaine induces cardiac depression, which is resistant to treatment. Therefore early recognition of its development is important so that the injection of bupivacaine can be discontinued promptly. We compared the efficacy of continuous mixed venous oxygen saturation (cSvO2) monitoring with that of the mean arterial blood pressure (MBP) monitoring in terms of the prediction of cardiac output (CO) changes in anesthetized dogs with bupivacaine-induced cardiovascular depression. METHODS: Bupivacaine was infused to pentobarbital-anesthetized mongrel dogs (n = 8) at a rate of 0.5 mg/kg/min until the MBP decreased to 40 mmHg or less (end of bupivacaine infusion; BIE). We defined the early period as the interval from baseline till 30 minutes after the bupivacaine infusion and the late period as that after the 30 minutes till BIE. We monitored cSvO2 with a fiberoptic pulmonary artery catheter. The MBP and CO were measured every ten minutes after the initiation of the bupivacaine infusion. Arterial blood gas analysis, mixed venous gas analysis, measurement of serum electrolyte concentrations and serum bupivacaine concentrations were performed simultaneously. The relationship between CO versus cSvO2 or versus MBP was compared retrospectively by regression analysis. RESULTS: The Pearson's correlation coefficients between CO and cSvO2 were 0.782 (r2 = 0.6111, P 0.05) in the early period and 0.799 (r2 = 0.6381, P < 0.01) in the late period. CONCLUSIONS: cSvO2 is superior to MBP for the prediction of CO changes in bupivacaine-induced cardiac depression in dogs, especially in the early period. We might expect a profound reduction of CO when MBP begins to decrease in the late period.

Effect of Saline-Filled or Viscous Lidocaine-Filled Cuff on the Laser-Induced Polyvinyl Chloride Endotracheal Tube Fires and Tidal Volume / 대한마취과학회지

BACKGROUND: There have been a lot of methods that prevent catatrophic airway fires during laser surgery, but none of them can protect endotracheal tube cuff exposed directly to laser beam. This study was performed to know the preventive effect of viscous lidocaine-filled cuffs on laser-induced combustion, and to know how long we can maintain positive pressure ventilation if laser beam broke out cuff perforation. METHODS: Transparent acrylic trachea attached to artificaial lung was intubated with 8.0 ID polyvinylchloride endotracheal tube. Cuff was filled with 8ml of saline or saline and viscous lidocaine mixture with 2:1 or 4:1 ratio. Positive pressure ventilation with air in tidal volume of 500 ml was begun. The laser output was set to 10 watt/sec in the continuous mode with beam diameter of 1 mm. Laser beam was directed perpendicularly at the part of the cuff protruding between endotracheal tube shaft and acrylic trachea, and laser emission was continued until the cuff was perforated or combusted. RESULTS: There was no case of laser-induced fires. After the perforation of cuff, the tidal volume was slowly decreased in 2:1 mixture of saline and viscous lidocaine filled cuff compared to others (P<0.05). CONCLUSION: 2:1 mixture of saline and viscous lidocaine may be used as an efficient inflating material of endotracheal tube cuffs on laser airway surgery.

Nasotracheal Intubation Using Fiberoptic Bronchoscope and Guidewire in a Pediatric Mandibular Fracture Patient: A case report / 대한마취과학회지

Although the endotracheal intubation using laryngoscope can usually be performed under general anesthesia, it may be very difficult in situations such as head and neck trauma, hemorrage, or deformity. Recently we performed antegrade fiberoptic nasotracheal intubation with a guide wire. A 15-month aged female child with mandibular fracture was scheduled for open reduction and internal fixation under general anesthesia. She was anticipated difficult intubation due to displacement of the fracture site. After induction of anesthesia, we passed an adult fiberoptic bronchoscope (O.D. 3.8 mm, LF-2, Olympus optical co, Japan) to vocal cord via right nostril. Then a guidewire was inserted through the suction port of bronchoscope, and bronchoscope was removed in a state of guidewire in situ. We slid the endotracheal tube over guidewire according to Seldinger's technique. We think that nasotracheal intubation using an adult fiberoptic bronchoscope and a guidewire is good for children under 2 years old who are expected the difficult intubation.

Attenuating Effect of cAMP on Hypoxic Pulmonary Vasoconstriction in the Isolated Perfused Rat Lungs / 대한마취과학회지

BACKGROUND: Pulmonary vessels constrict when they are exposed to hypoxia, unlike other vessels. It is hypothesized that the decreased concentration of cAMP in the hypoxic condition causes this reaction, HPV (hypoxic pulmonary vasoconstriction). When cAMP concentration is increased by either activating adenylate cyclase, using adenosine, or inhibiting the cAMP hydrolysing enzyme, phosphodiesterase type 3, using amrinone, then HPV can be reversed. The aims of this study were to develop HPV in an isolated perfused rat lung preparation, and to investigate the vasodilating effects of adenosine and amrinone on HPV. METHODS: Isolated lungs from male rats (270 330 g) were ventilated with a normoxic gas mixture (21%O2-5%CO2-74%N2) or a hypoxic gas mixture (3%O2-5%CO2-92%N2) alternately, and perfused with calcium-containing perfusate solution. Adenosine (6 x 100-2 microgram, n = 6) and amrinone (5 x 101-3 microgram, n = 6) were mixed to perfusate solution, and the initial hypoxic pressor response { Pin = Pmax (maximum pulmonary artery pressure) - Pin (initial pulmonary artery pressure)} and hypoxic pressor responses after drug administration { Pdrug = Pmax (maximum pulmonary artery pressure) - Pbase (baseline pulmonary artery pressure)} were measured. Meclofenamate was used to block prostaglandin-mediated vasorelaxation. RESULTS: Adenosine did not decrease Pdrug compared to Pin. But amrinone inhibited HPV effectively a with a linear dose-response relationship (r = 0.842, P< 0.05). y = 26.72 x log (x) 35.79y: % relaxation = 100 [ Pdrug/ Pin] 100 , x: amount of drug, microgram, CONCLUSIONS: Amrinone attenuated HPV, and it can be concluded that increased levels of cAMP helpful to relax pulmonary vessels in hypoxic condition.

Anesthetic Management in a Patient with Anaphylaxis to Thiopental: A case report / 대한마취과학회지

The incidence of anaphylaxis to intravenous agents used for general anaesthesia is reported as about 1 : 6000. Despite appropriate treatment, mortality is reported as about 6%, thus it is important to try to minimize the risk by prevention. A adequate investigation, communication and avoidance of drugs responsible with the use of pretreatment and alternative techniques, the risk of second reaction should be reduced. A patient who has the history of anaphylactic shock to thiopental, for the induction of anesthesia was scheduled for subtotal gastrectomy. Skin test confirmed that she had a hypersensitivity to a thiopental. We performed combined general and spinal anesthesia. She was premedicated with dexamethasone and pheniramine malate in the operating room. Spinal blockade is up to T6 by 0.5% tetracaine. Then, anesthesia was induced with propofol and midazolam. There is no need for muscle relaxant drugs and anesthesia was maintained with isoflurane, N2O, O2. Subtotal gastrectomy was done without event. Combined general and spinal anesthesia affords the anesthesiologist the opportunity to lower the local anesthetic doses, to avoid using many kinds of intravenous drugs (muscle relaxants, opioids, benzodiazepine, etc.) and to approach a kind of anesthesia that is close to the ideal anesthesia.

A Comparison of Pressure Controlled Ventilation and Hybrid Ventilation in Rabbits / 대한마취과학회지

BACKGROUND: Intermittent positive pressure is required to overcome pulmonary airway resistance during inspiration and to deliver an adequate tidal volume. Previous animal experiments have shown that mechanical ventilation may worsen the lung injury when high airway pressure and large tidal volume are required to achieve adequate ventilation and oxygenation. Many ventilatory strategies have been developed to minimize airway pressure increase for the less compliant lung. Intratracheal pulmonary ventilation (ITPV) was developed to allow a decrease in physiological dead space during mechanical ventilation. METHODS: Pressure controlled ventilation (PC) has been compared with hybrid ventilation (HV) which consists of PC and ITPV in 7 rabbits. A reverse thrust catheter (RTC) was introduced into an endotracheal tube (ETT) through an adapter and positioned just above the carina inside the ETT. Fresh gas flowed continuously along the gap between inner cannula and outer cap in the expiratory direction. Gas was intermittently re-directed into the lung as a tidal volume by a valve on the expiratory circuit with ventilatory mode of PC to make HV. Peak inspiratory pressure (PIP) and dead space (VD) at various respiratory rates (RR) of 20/min, 40/min, 80/min and 120/min were compared between PC and HV while maintaining normal PaCO2. RESULTS: The PIPs of PC were 12.4 +/- 3.4 cmH2O, 9.0 +/- 2.7 cmH2O, 8.8 +/- 2.7 cmH2O, and 7.6 +/- 2.5 cmH2O at RR of 20/min, 40/min, 80/min and 120/min, respectively. The PIPs of HV were 9.2 +/- 3.2 cmH2O, 6.2 +/- 1.7 cmH2O, 5.0 +/- 2.0 cmH2O, and 4.5 +/- 1.8 cmH2O at the same RR of 20/min, 40/min, 80/min and 120/min, respectively. The VDS of HV were lower than those of PC. CONCLUSION: It can be concluded that ITPV can be applied as a HV to minimize airway pressure under the setting of PC.

The Effect of Atropine on Hemodynamics during Spinal Anesthesia / 대한마취과학회지

Background: The major complications of spinal anesthesia are hypotension and bradycardia. In normal condition, hypotension stimulates baroreceptor reflex and compensatory tachycardia is occured. But during spinal anesthesia, there is possibility of a blockade of cardiac sympathetic nerve fibers which would result in increased vagal tone and depress compensatory baroreceptor reflex which is activated during hypotension. Atropine is an anticholinergic agent whose predominant cardiovascular effect was known as increasing heart rate at clinical dose. The purpose of this study was to evaluate hemodynamic effect of atropine during spinal anesthesia. Methods: We compared heart rate, systolic, diastolic and mean arterial pressures and cardiac output in 26 patients of ASA physical status 1, 2 before and after intravenous injection of atropine sulfate 0.01 mg/Kg during spinal anesthesia. Hemodynamic parameters were measured just prior to and 1, 2, 3, 4, 5, 10 minutes after atropine sulfate intravenous injection. The data were analyzed by repeated measures ANOVA. Results: Heart rate, mean blood pressure and diastolic blood pressure after atropine sulfate injection increased with significance. Conclusion: These findings suggest that during spinal anesthesia atropine is effective to produce tachycardia with a dosage of 0.01 mg/Kg in humans. Also hypotension might be improved because atropine makes mean blood pressure and diastolic blood pressure increase.

Usefulness of PAR Score and Modified PADSS as Patient Discharge Criteria in Ambulatory Surgery / 대한마취과학회지

Background: Although an ambulatory surgical practice continues to increase, there is a few data exist about patient discharge criteria. This study was undertaken to evaluate the usefulness and safety of Aldrete PAR (postanesthetic recovery) score and modified PADSS (modified postaneathesia discharge scoring system) on ambulatory surgery patients for recovery in Korea. Methods: Demographic, anesthetic data, Aldrete PAR score and modified PADSS on 279 patients were recorded. The time to dicharge, from recovery room and postoperative complications were evaluated, also. Results: PAR score and modified PADSS are correlated to length of stay in ambulatory surgery center. 24hr after discharge, 16% patients complained postoperative complications. Pain was most frequent postoperative complication. The PAR score was correlated with the occurrence of the complication. Conclusion: PAR score and modified PADSS are useful scoring systems to evaluate patients and make a decision to discharge the patients from ambulatory surgery center in safe.