Intubation through a Laryngeal Mask Airway by Fiberoptic Bronchoscope in an Infant with a Mass at the Base of the Tongue: A case report / 대한마취과학회지

Failed or difficult tracheal intubation remains an important cause of mortality and morbidity during anesthesia, especially in infants with anatomical or pathological abnormalities of the airway.We report on a 4.1 kg, 85-day-male infant with a thyroglossal duct cyst at the tongue base who could not be conventionally ventilated and intubated in the supine position.The infant was intubated with a 3-mm endotracheal tube through the laryngeal mask airway (LMA) with guidance of a fiberoptic bronchoscope (FOB).However, the pilot balloon did not pass through the 1.5-mm LMA conduit.After cutting the pilot balloon, we removed the LMA and inserted a central venous catheter guide-wire through the endotracheal tube to increase the endotracheal tube to 3.5 mm.This maneuver allowed us to secure the airway without further problems.

Effect of BMI and Patient Positioning on Airway Pressures and Respiratory Compliance during Laparoscopic Surgery / 대한마취과학회지

BACKGROUND: Conventional laparoscopic surgery requires a pneumoperitoneum with CO(2) and a change in the patient positioning. Because of the pneumoperitoneum, the peak and plateau airway pressure and respiratory compliances can change compared with initial value. Obesity also affects the patient's respiratory mechanics. The aim of this study was to determine the correlation between the patient's positioning and a pneumoperitoneum with the changes in the respiratory mechanics, and to examine the relationship between the patient's BMI and the changes in therespiratory mechanics. METHODS: Fifty patients undergoing a laparoscopic cholecyctectomy and had no pulmonary pathology were enrolled in this study. The patient's basic data were obtained and the Body Mass Index (BMI) was calculateed. Conventional induction and maintenance of anesthesia were carried out, and each patient was fully relaxed with a rocuronium during the procedure. The change in the respiratory mechanics was checked 5 minutes after induction, the time that the pneumoperitoneum had been induced, and the end of surgery with the supine and 10degrees tilting of the Trendelenburg and reverse Trendelenburg position. RESULTS: There was approximately a 30% reduction in dynamic compliances before and after inducing pneumoperitoneum with CO(2) at each position and a negative correlation between the BMI and the dynamic compliance. There were no significant differences in the respiratory mechanics withe the different patient positions. CONCLUSIONS: The respiratory mechanics are influenced by an increase in the patient's BMI and induced pneumoperitoneum but not by a 10degrees tilting of the reverse Trendelenburg and Trendelenburg position.

Anesthetic Management of Difficult Tracheotomy with Fiberoptic Bronchoscope: A case report / 대한마취과학회지

The purpose of tracheotomy is to obtain secure airway for difficult airway management and long-term lung ventilation. Tracheotomy is an invasive procedure with the possibility of severe complications, but it is the last choice for difficult airway management. To perform tracheotomy is difficult in patients with anatomically distorted trachea, screened trachea by mass, fibrosis or adhesion and obesity. We report the experience of successful tracheotomy in the patient of severely distorted airway due to previous surgeries with the aid of the light illumination of fiberoptic bronchoscope.

A Survival Case of a 630 gram Extremely Low Birth Weight Neonate after Surgery for the Small Bowel Perforation

The surgical care of neonates, born weighing less then 1000 gram (Extremely Low Birth Weight; ELBW), is a very challenging problem to the pediatric surgeons. We report a survival case in which a successful operation for the spontaneous intestinal perforation was performed at the time when the baby weighed 630 g after 25.6 weeks' gestation. The child not only survived but also appears developmental normal at two years of age. The case is the smallest reported survivor in Korea after surgery. The cooperation between the pediatric surgeon and neonatologist is very important in the surgical management of ELBW neonate.

Effects of Acute Normovolemic Hemodilution under Induced Hypotension on Blood Saving and Homologous Transfusion in Orthognathic Two Jaw Surgery / 대한마취과학회지

BACKGROUND: To avoid complications of homologous transfusion, many methods are being used in patients who undergo an operation, and autologous transfusion is the most popular modality. Acute normovolemic hemodilution (ANH) is recognized as the easiest, the most economical and valuable autologous blood saving method among the types of autotransfusion. This study was performed to investigate the clinical usefulness of ANH under induced hypotensive anesthesia to reduce blood loss and homologous transfusion in orthognathic two jaw operation. METHODS: Thirty patients were randomized divided into two groups; with ANH (n = 15) and without ANH (n = 15). The surgery was limited to one surgeon, with genioplasty, and no bone graft. All patients were pre-donated 2 units of autologous blood before operation. All the surgery was done under induced hypotension by nitroglycerine and esmolol, target mean arterial pressure was aimed at 70% of preoperative blood pressure. In with ANH group, autologous blood were procured immediately after anesthetic induction while 6% hydroxyethyl starch solution were infused to maintain normovolemia until lowering hematocrit to 28%. RESULTS: The two groups did neither differ significantly with demographic data and preoperative evaluation finding. Nor in operation time, surgeon's satisfaction to surgical field, serial central venous pressure, hematocrit's value, prothrombin time, activated partial thromboplastin time. All patients needed transfusion of pre-donated 2 units of autologous blood during operation, but there was significantly reduced demand for homologous packed RBC transfusion in the with ANH group compared with the control group (0.0 0.0 unit vs. 1.7 1.2 unit, P = 0). Blood saving effects was so greater in with ANH group (total blood loss; 1110.0+/-154.9 cc vs. 833.3+/-156.6 cc, P = 0). In addition, the amount of agents for induced hypotension was smaller in with ANH group (nitroglycerine: 11.3+/-2.4 mg vs. 9.9+/-2.4 mg, P = 0.012, esmolol: 52.0+/-28.2 mg vs. 14.6+/-8.3 mg, P = 0). CONCLUSIONS: ANH with pre-donated autologous blood under induced hypotension can reduce intraoperative blood loss and homologous transfusion requirements in orthognathic two jaw operation.

Effects of Postoperative Patient Controlled Epidural Analgesia in Pediatric Patients Undergoing Lower Extremity Surgery / 대한마취과학회지

BACKGROUND: A limited number of studies have been conducted on postoperative epidural analgesia in pediatric patients. There have been primarily dealt with spinal or abdominal surgeries where multiple dermatomal segments needed to be blocked and morphine was given either through the caudal approach or by direct catheter placement. This study evaluated the safety and efficacy of postoperative continuous patient controlled epidural analgesia (PCEA) in children undergoing lower extremity surgery using a bupivacaine and fentanyl via lumbar approach. METHODS: The patient population consisted of 40 children ranging in age from 5 to 12 years. Patients were randomly divided into two groups according to postoperative pain relief regimen; the control group received an intramuscular injection of ketorolac 1 mg/kg t.i.d. and meperidine 0.5 mg/kg p.r.n., and the epidural group received PCEA (0.1% bupivacaine + fentanyl 2 microgram/ml) through an epidural catheter positioned at the surgical dermatomal level of the spinal cord. In the epidural group the volume of the initial dose was 1 ml/segment in children 10 years of age. The basal infusion rate was 0.1 ml/kg/hr (bolus: 0.05 ml/kg, lockout time: 30 minutes). Pain scores were measured upon arrival at the ward, and 6 and 24 hours thereafter. RESULTS: The epidural group had significantly lower pain scores and minimal side effects. A significant correlation was observed between the bolus number and the incidence of nausea/vomiting in the epidural group. CONCLUSIONS: This study shows that PCEA targeted at the surgical dermatome is a safer and more effective regimen for postoperative pain relief than conventional postoperative pain relief in pediatric patients undergoing lower extremity surgery.

Comparative Study of Isobaric Bupivacaine Spinal Anesthesia in the Supine and Prone Positions / 대한마취과학회지

BACKGROUND: Isobaric bupivacaine has same baricity as cerebrospinal fluid and therefore, so it remains at the level of injection. But, the risk of high spinal anesthesia exist, because increased intrathecal pressure is possible in prone position as isobaric bupivacaine has mild hypobaricity at body temperature but is isobaric at room temperature. So, we studied the influence of the position of the blockade of spinal anesthesia in isobaric spinal anesthesia. METHODS: We studied 26 patients undergoing elective surgery for which spinal anesthesia was considered appropriate. One group (the P group) were scheduled for surgery in the prone position with a frame (n = 13), the second group (the S group) were scheduled for surgery in the supine position (n = 13). Patients were injected with 12 mg of 0.5% isobaric bupivacaine at L3-4 in the lateral decubitus position with a 22 G spinal needle at the rate of 0.2 ml/sec. We then assessed anesthetic blockade level, heart rate, and blood pressure. RESULTS: The height of the sensory block in the prone position group was at the 10th thoracic dermatome, whereas in the supine position this was at the 8th thoracic dermatome at 15 minutes. There was a little difference between the two groups, but this was insignificant statistically. CONCLUSIONS: Both the supine and the prone positions are suitable for isobaric spinal anesthesia with bupivacaine. Isobaric spinal anesthesia in the prone position with a frame is as safe as in the supine position. Spinal anesthesia with isobaric bupivacaine is considered to have a low risk of high spinal anesthesia and a low complication level in the prone position with a frame, as for the supine position.

Benefits of a ProSeal Laryngeal Mask Airway in a Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: The ProSeal laryngeal mask airway (PLMA) is a new laryngeal mask device with a larger cuff and a drainage tube. This study was designed to assess the usefulness and the safety of the PLMA in a laparoscopic cholecystectomy. METHODS: Forty patients undergoing a laparoscopic cholecystectomy were randomly allocated to two groups; an endotracheal tube (ETT) group or a PLMA group. Anesthesia was induced with intravenous fentanyl and propofol and maintained with TCI-propofol. Blood pressure, heart rate, peak inspiratory pressure, peripheral O2 saturation (SpO2), end-tidal CO2 tension (PETCO2) and PaCO2 was measured during the operation. The incidence of gastric content regurgitation and gross pulmonary aspiration were evaluated. Postoperatively, SpO2, the visual analogue scale (VAS) of pain, nausea and vomiting (PONV), and sore throat were evaluated at 30 minutes intervals in post-anesthetic care unit (PACU) and at night. RESULTS: There were no significant differences in intraoperative PIP, SpO2, PETCO2, postoperative SpO2, VAS scores, PONV, and sore throat between the two groups. Gross pulmonary aspiration was not found in either group, but minimal gastric regurgitation occurred in 2 cases of the ETT group and 1 case of the PLMA group. CONCLUSIONS: We concluded that there were no differences in patient safety and adequate ventilation for a laparoscopic cholecystectomy between the ETT group and PLMA group. Moreover, there were no increases in blood pressure and heart rate in PLMA group during insertion/intubation.

How Much are Anesthesiologists Exposed to Electromagnetic Fields in Operating Rooms?

Numerous electronic devices have been introduced into the operating room. Although little is known about the relationship between exposure to electromagnetic fields (EMF) and health hazards, some authors reported its association with cancer or other diseases. We measured the amount of EMF exposure that an anesthesiologist gets in the operating room. The density of the magnetic field was checked by an extremely low frequency (ELF) field strength measurement system in the 19 operating rooms of our hospital. We measured the magnetic field intensity at a distance of 30 cm, 50 cm, and at the place where the anesthesiologist usually stands from the center of the main monitor. The average exposure quantities of magnetic fields in 19 operating rooms were 2.22 +/- 1.13 mG at 30 cm, 1.29 +/- 0.84 mG at 50 cm and 1.00 +/- 0.78 mG at the anesthesiologist's standing points respectively. Because quantities over 2 or 3 mG were accepted to be high radiation levels of EMF by many reports describing the hazards of EMF, we set 2 mG to be the cutoff value. In some of the 19 operating rooms, the measured EMF density exceeded our cutoff value. Although the health hazards related to EMF exposure are still equivocal, anesthesiologists should consider making an effort to improve their environment and reduce their exposure to EMF.

Effects of Dexamethasone on Neuromuscular Transmission in a Phrenic Nerve-Hemidiaphragm Preparation in the Rat / 대한마취과학회지

BACKGROUND: MacFarlane and Rosenthal reported a case of acute quadriplegia after nondepolarizing muscular blocking agents in status asthmaticus patient treated with high doses of corticosteroid. Reports regarding the reactions of glucocorticoid treated muscles to neuromuscular blocking agents are sparse and inconsistent. The aims of this study were to examine the degree of muscle atrophy and its effects on sensitivity to neuromuscular blocking agents in relation to the dose and duration of dexamethasone. METHODS: Sixty Sprague-Dawley rats were divided into six groups. They were treated daily with dexamethasone 0.4 mg/kg and 4 mg/kg daily for 1 week or 3 weeks. The two control groups were treated with normal saline. The day after treatment, the dose-response curves of vecuronium were measured using a phrenic nerve-hemidiaphragm preparation. To classify muscle fiber, the diaphragm was stained for myofibrillar adenosine triphosphatase after alkaline and acid preincubation, and a morphometric examination was carried out. RESULTS: The diaphragmatic muscle in rats treated with long term, high dose dexamethasone showed significant atrophy. For the short term, low dose dexamethasone group, the ED50 and ED95 of vecuronium decreased 41.5% and 26.8% compared to those of the control group, respectively (P<0.05). However, the ED50 of vecuronium in the long term, high dose dexamethasone group increased 22.2% compared to that of the control group (P<0.05). CONCLUSION: This study suggests that sensitiviy to vecuronium was not modulated by dexamethasone-induced muscle atrophy. Quantitative changes of receptors at the neuromuscular junction or some anoother process might be responsible for this change.

Congenital Tracheomalacia Associated with Esophageal Atresia

This is a case of tracheomalacia associated with esophageal atresia. An 11-month-old- male boy presented with a life-threatening apneic spell after correction of esophageal atresia (Gross type C). After complete exclusion of the other possible causes of the apneic spell, the presumptive diagnosis of tracheomalacia was made with fluoroscopy and 3-dimensional chest CT. The final diagnosis was made with rigid bronchoscopy under spontaneous respiration. The aortopexy was performed with intraoperative bronchoscopic examination. The postoperative period was unremarkably uneventful. The patient was discharged 9 days after the aortopexy and has remained well to date (5 months after the aortopexy).

Successful Weaning after Diaphragmatic Plication in an Infant with Phrenic Nerve Palsy Resulting from Removal of Cavernous Lymphangioma / 대한구급학회지

Phrenic nerve palsy is a well-known complication following cardiac surgery in children. The incidence is approximately 1~2%. In infants and young children, it often causes a life-threatening respiratory distress. They must be treated with mechanical ventilation in the ICU. Many patients with phrenic nerve injury who is impossible to wean from a ventilator are candidates of diaphragmatic plication. Diaphragmatic plication is performed to restore the normal pulmonary parenchymal volume by replacing the diaphragm to its proper location. This is a case of 2-months-old infant who had phrenic nerve palsy after the removal of cavernous lymphangioma of the chest. He underwent 4 operations to remove the mass and to have pericardiotomy. We tried to wean him from the ventilator but failed several times in the ICU. After 4th operation, right diaphragmatic elevation was noted from the chest X ray. Phrenic nerve palsy was confirmed with fluoroscopy and he underwent diaphragmatic plication on 42 days after his 4th operation. Three days after the diaphragmatic plication, weaning was successfully carried out.

The monitoring of somatosensory evoked potentials and neurologic complications in aneurysm surgery

Somatosensory evoked potential (SSEP) changes during cerebral aneurysm surgery and their relationship to postoperative neurologic complications have been studied on many occasions. However, it is still a matter of debate whether SSEP monitoring is really helpful in detecting or preventing neurologic complications. We studied 87 patients undergoing aneurysm surgery of the anterior cerebral circulation and SSEPs were monitored in 60 of these patients. All patients were grade 2 by the subarachnoid hemorrhage (SAH) grading system. Median nerve SSEP was monitored for middle cerebral or internal carotid artery aneurysms and posterior tibial nerve SSEP for anterior cerebral artery aneurysms. A decrease in the cortical amplitude of more than 50%, compared with control, was considered significant and interventions were then taken to reverse the SSEP. The pre- and postoperative neurologic deficits of each patient were evaluated immediately before and after surgery. No significant difference was found in the incidence of postoperative neurologic complications in the SSEP monitored (15% [9/60]) and unmonitored patients (22% [6/27]). In the SSEP monitored patients, the amplitudes of SSEPs decreased significantly in 14 patients and 4 of these showed neurologic complications. However, SSEP amplitudes were not significantly changed in 46 patients, and 5 of these showed neurologic complications. Significant changes in the amplitude of SSEP might represent neuronal injury, but the absence of change in the SSEP cannot guarantee patient safety. Our results suggest that SSEP monitoring may be useful for detecting the danger of neuronal injury, but that it does not reduce the incidence of neurologic complications in aneurysm surgery.

The changes in delivered oxygen fractions using laerdal resuscitator bag with different types of reservoir

One of the disadvantages of the Laerdal resuscitator bag is that it does not deliver a high concentration of oxygen without a reservoir and an appropriate technique of ventilation. With a specific device that is able to compress a resuscitator bag mechanically at a regular volume, ventilator rate, and speed, we evaluated the effects of various factors (the tidal volume, the ventilator rate, the oxygen flow rate, the type of reservoir) of the Laerdal resuscitator bag during positive pressure ventilation that affect the delivered oxygen fraction (FDO2) and also whether 250 mL and 500 mL corrugated tubes could be used as substitutes for the reservoir bag. The 250 mL corrugated tube increased the FDO2 to over 96% with an oxygen flow rate of 15 L/min. The 500 mL corrugated tube increased the FDO2 to over 96% with an oxygen flow rate of 10 L/min regardless of the ventilator rate at a fixed tidal volume of 500 mL. At the identical fixed tidal volume of 500 mL, the 1,600 mL reservoir bag increased the FDO2 to over 92% with an oxygen flow rate of 5 L/min and to over 96% at 7.5 L/min regardless of the ventilator rate. We concluded that the FDO2 of the Laerdal resuscitator bag depends on various factors such as tidal volume, ventilator rate, oxygen flow rate, and type of reservoir and both the 250 mL and 500 mL corrugated tubes can be used as substitutes.

The Effect of the Injected Volume on the Spread of Spinal Anesthesia with Hypobaric Tetracaine / 대한마취과학회지

BACKGROUND: The properties of hypobaric spinal anesthesia are excellent in sensory and motor block with low concentration solutions, increased venous return, and hemodynamic stability. Much volume is needed with hypobaric spinal anesthesia because low concentration solutions are used. The purpose of this study was to examine the effects of the injected volume on the level of anesthesia in hypobaric spinal anesthesia during a total hip replacement. METHODS: Twenty-seven adult patients scheduled for a total hip replacement were assigned randomly to two groups, one with 0.1% (n = 14), and the other with 0.2% (n = 13) hypobaric tetracaine spinal anesthesia. 8 mg of tetracaine was used for male patients and 7 mg for female patients. Hence the injected volumes were 8 ml for male and 7 ml for female patients in 0.1% solution and 4 ml for male and 3.5 ml for female patients in 0.2% solution, respectively. Epinephrine was mixed to either solution in concentrations of 1:200,000. The speed of injection was fixed at the rate of 0.2 ml/sec. RESULTS: The height of sensory block with the 0.1% was one dermatome higher (T5.7) than with the 0.2% tetracaine solution (T6.7). The time for sensory block (11.4 min vs 12.3 min) and the time for motor block (10.0 min vs 15.0 min) with 0.1% was shorter than that with the 0.2% tetracaine solution. The duration of sensory block and the duration of motor block were not significantly different in either groups. Complete motor block was achieved in all patients. CONCLUSIONS: Both 0.1% and 0.2% hypobaric tetracaine spinal anesthesia are suitable for a total hip replacement. However we got better results with 0.1% than with 0.2% tetracaine such as rapid and high sensory block with rapid motor block.

The Effect of Increased Minute Ventilation on the Changes of End-Tidal Isoflurane Concentration and Bispectral Index / 대한마취과학회지

BACKGROUND: An increase in ventilation is known to accelerate the rate of the rise of alveolar concentration of inhalation anesthetics and increase the rate of anesthetic induction. However, it is still debatable whether or not a rise of alveolar isoflurane concentrations by increased minute ventilation (MV) actually increases the depth of anesthesia. METHODS: After anesthetic induction by intravenous thiopental and succinylcholine, and after the bispectral index (BIS) had recovered to 75 after intubation, isoflurane anesthesia was begun (inspired concentration:2 vol.%, respiratory rate:12/min, tidal volume: group I; 8 ml/kg, group II; 12 ml/kg). BIS, spectral edge frequency (SEF), blood pressure, pulse rate were recorded 1 minute before induction, and 1, 2, 3, 4, 5, 7 and 10 minutes after isoflurane anesthesia. End-tidal concentrations of isoflurane and CO2 (ET-iso and -CO2) were recorded at 1, 2, 3, 4, 5, 7 and 10 minutes after isoflurane anesthesia. RESULTS: The increase of ET-iso and the decrease of ET-CO2 were significantly fast in group II. There was no difference in BIS and SEF between the two groups. CONCLUSIONS: Increasing MV induced a rapid rise of alveolar isoflurane concentrations, but changes of BIS and SEF were not affected by increased MV.

The Effects of Desflurane on Ca2+ Release from the Myocardial Sarcoplasmic Reticulum in Vitro / 대한마취과학회지

BACKGROUND: The purpose of this study is to examine the effect of Desflurane on myocardial contractility and cellular electrophysiologic behabior in isolated guinea pig and rat right ventricular papillary muscle. METHODS: The isometric force of a guinea pig ventricular papillary muscle was studied in normal and 26 mM Tyrode's solution at various stimulation rates. Experiments using rat papillary muscles under normal Tyrode's solution at resting-state (RS) and using guinea pig papillary muscles under low Na Tyrode's solution (25 mM) were performed to evaluate the effect on Ca2+ release from the sarcoplasmic reticulum (SR). Normal and slow action potentials (APs) were evaluated by using a conventional microelectrode technique. Effects of desflurane on SR function in situ were examined by its effect on rapid colling contractures (RCCs). 1 MAC (end-tidal concentration: 6%) and 2 MAC desflurane were applied. RESULTS: Desflurane equivalent to 6% and 12% depressed guinea pig myocardial contractions in the control to -70% and -40% from RS to 3 Hz stimulation rates. Contractile force after rest in rat and guinea pig myocardium under low Na Tyrode's solution showed modest depression. In the partially depolarized, beta-adrenergically stimulated myocardium, 6% and 12% desflurane caused marked depression of late force (6%: -60%, 12%: -80%) with moderate changes of early peak force (6%: -20%, 12%: -40%). RCCs were abolished at 6% concentration. CONCLUSIONS: The direct myocardial depressant effects of desflurane is slightly greater to those seen with isoflurane. The rapid initial release of Ca2+ from the SR by depolarization seems to be modestly depressed, although certain release pathways induced by rapid colling appear to be markedly depressed.

The Direct Myocardial Depressant Effect of Methylmethacrylate Monomer in vitro: Mechanical and Electrophysiological Actions / 대한마취과학회지

BACKGROUND: Methylmethacrylate monomer (MMA) bone cement has been associated with sudden systemic hypotension. The present study was aimed to explore the mechanism of direct myocardial depressant actions of MMA. METHODS: The isometric contraction of isolated guinea pig's right ventricular papillary muscle was measured. Normal and slow action potentials were evaluated by a conventional micro-electrode technique. The effects of MMA on sarcoplasmic reticulum (SR) function were evaluated by its effect on: rapid cooling contractures, rested state contraction of rat papillary muscle in normal Tyrode's solution and of guinea pig's papillary muscle in low Na+ Tyrode's solution. To measure the inward calcium currents (ICa), whole cell patch clamp techniques were applied. RESULTS: MMA caused a dose-dependent depression of the peak force (PF) and maximal rate of peak force (dF/dt-max). About a 30% depression of PF was shown at rested state (RS) contraction in rat myocardium and under low Na+ Tyrode's solution in guinea pig myocardium, respectively. In the 26 mM K+ Tyrode's solution, MMA caused dose-dependent depression of late force development without alteration in early force development. MMA depressed rapid cooling contracture accompanied by prolongation of time to peak contracture. MMA did not alter the amplitude or maximum depolarization rate of normal and slow action potentials. Action potential durations were significantly reduced. In patch clamp studies, MMA reduced ICa in a dose-dependent manner. CONCLUSIONS: MMA depressed cardiac contractility in a dose-dependent manner and may be partly related to the depression of Ca2+ influx through the cardiac membrane. SR Ca2+ release seems to be mildly inhibited by MMA. Based on common clinical concentrations, the direct myocardial depressant effect of MMA may not be a main cause of hypotension during an operation.

The Changes in Delivered Oxygen Fractions Using Laerdal Resuscitator Bag with Corrugated Tubes / 대한마취과학회지

BACKGROUND: In emergency rooms or intensive care units, we have shown delivery of higher fractions of oxygen promptly for respiratory or cardiac arrest patients by using resuscitating instruments, especially the resuscitator bag. Previously we studied the variables affecting the fraction of delivered oxygen (FDO2) under varying ventilating techniques and conditions. In this paper, using corrugated tubes as substitute for reservoir bag, we measured FDO2 and compared two. METHODS: We designed a special wooden box, which held the Laerdal resuscitator bag. We measured the FDO2 with or without reservoir bags and corrugated tubes at various tidal volumes, respiration rates and oxygen flows. RESULTS: With a 500 ml corrugated tube, FDO2 were higher than with a 250 ml corrugted tube but lower than with a reservoir bag. CONCLUSIONS: Corrugated tube is less effective to deliver high fractions of oxygen than the reservior bag, but it is acceptable to use corrugated tube as a substitute for a reservior bag than not to use it at all.

Reorganizatin of Blood Ordering Practice for Elective Surgery / 대한임상병리학회지

BACKBROUND: The over-preparation of blood for elective surgery causes some problems such as returning of blood, inefficient task and loss of reagent. Even though "Type & Screen" method helps solve such problems, we need to make a great effort to inform clinician of it. In Severance hospital, 1986 MSBOS had been established for the first time and revised in 1991. Recently, as various side effects of transfusion have been known and operation technique developed, blood usage is being decreased. Therefore, we try to revise maximal surgical blood order schedule(MSBOS) investigating RBC utilization for elective surgery in Severance hospital, 1999. METHODS: We investigated RBC utilization for elective surgery of the adult patient and, pre-op hemoglobin level, number of transfused patients, mean blood amount of transfused patients and mean blood amount of all operated patient referring to anesthesiologic record and blood delivery sheet in Severance hospital during 6 months from January through June 1999. RESULTS: The blood utilization of the period has been significantly decreased, compared with the previous reports(Korean J Blood Transfusion 1991;2:183-90) except in cardiovascular surgery. CONCLUSIONS: We could revise the guidelines for ordering blood on the basis of above results. Afterthis, MSBOS should be reestablished at regular intervals to improve blood utility.