Antibacterial effect of lidocaine in various clinical conditions

BACKGROUND: Infection, one of the complications associated with procedures, can cause fatal outcomes for patients. Although the local anesthetic agent we use is less susceptible to infection due to its antibacterial action, we performed this study to check the change in the antibacterial effect of lidocaine in various clinical conditions. METHODS: After exposing lidocaine to five contaminated environments, we checked on whether the bacteria could be cultured in blood agar plate (BAP) media. In each contaminated environment, lidocaine was exposed for 4 h (n = 9) and 8 h (n = 9), and the results were compared. Lidocaine was swabbed with chlorhexidine (group A), brought into contact with saliva (group B), skin (group C), an operating room floor and an outpatient room floor (group D), operating room air for 24 h (group A-a), and outpatient room air for 24 h (group A-b). After exposure, the culture was initiated. RESULTS: In 2 of 9 BAP media where lidocaine was exposed to saliva (group B) for 8 h, growth of a colony was observed. In gram staining, it was found to be Streptococcus viridans. No bacteria were found in any other groups. CONCLUSIONS: Though lidocaine has strong antibacterial activity, it has been found that long-term exposure to a contaminated environment reduces its antibacterial activity and that drug contamination can be heavily affected not only by environmental but also human effects. Therefore, the use of aseptic drugs is necessary, and stopping the reuse of the drug is a way to prevent complications, including infection.

Myometrial relaxation of mice via expression of two pore domain acid sensitive K⁺ (TASK-2) channels

Myometrial relaxation of mouse via expression of two-pore domain acid sensitive (TASK) channels was studied. In our previous report, we suggested that two-pore domain acid-sensing K⁺ channels (TASK-2) might be one of the candidates for the regulation of uterine circular smooth muscles in mice. In this study, we tried to show the mechanisms of relaxation via TASK-2 channels in marine myometrium. Isometric contraction measurements and patch clamp technique were used to verify TASK conductance in murine myometrium. Western blot and immunehistochemical study under confocal microscopy were used to investigate molecular identity of TASK channel. In this study, we showed that TEA and 4-AP insensitive non-inactivating outward K⁺ current (NIOK) may be responsible for the quiescence of murine pregnant longitudinal myometrium. The characteristics of NIOK coincided with two-pore domain acid-sensing K⁺ channels (TASK-2). NIOK in the presence of K⁺ channel blockers was inhibited further by TASK inhibitors such as quinidine, bupivacaine, lidocaine, and extracellular acidosis. Furthermore, oxytocin and estrogen inhibited NIOK in pregnant myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed stronger inhibition of NIOK by quinidine and increased immunohistochemical expression of TASK-2. Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretch-activated channels in the longitudinal myometrium of mouse. Activation of TASK-2 channels seems to play an essential role for relaxing uterus during pregnancy and it might be one of the alternatives for preventing preterm delivery.

Mechanism of Relaxation Via TASK-2 Channels in Uterine Circular Muscle of Mouse

Plasma pH can be altered during pregnancy and at labor. Membrane excitability of smooth muscle including uterine muscle is suppressed by the activation of K+ channels. Because contractility of uterine muscle is regulated by extracellular pH and humoral factors, K+ conductance could be connected to factors regulating uterine contractility during pregnancy. Here, we showed that TASK-2 inhibitors such as quinidine, lidocaine, and extracellular acidosis produced contraction in uterine circular muscle of mouse. Furthermore, contractility was significantly increased in pregnant uterine circular muscle than that of non-pregnant muscle. These patterns were not changed even in the presence of tetraetylammonium (TEA) and 4-aminopyridine (4-AP). Finally, TASK-2 inhibitors induced strong myometrial contraction even in the presence of L-methionine, a known inhibitor of stretchactivated channels in myometrium. When compared to non-pregnant myometrium, pregnant myometrium showed increased immunohistochemical expression of TASK-2. Therefore, TASK-2, seems to play a key role during regulation of myometrial contractility in the pregnancy and provides new insight into preventing preterm delivery.

Wire-reinforced endotracheal tube fire during tracheostomy: A case report / 대한마취과학회지

Every operation could have a fire emergency, especially in the case of a tracheostomy. When a flammable gas meets a source of heat, the danger of fire is remarkable. A tracheal tube filled with a high concentration of oxygen is also a great risk factor for fire. Intra-tracheal tube fire is a rare, yet critical emergency with catastrophic consequences. Thus, numerous precautions are taken during a tracheostomy like, use of a special tube to prevent laser damage, ballooning of the tube with normal saline instead of air, and dilution of FiO2 with helium or nitrogen. Since the first recorded cases on tube fires, most of the fires were initiated in the balloon and the tip. In the present case report, however, we came across a fire incidence, which originated from the wire.

Transient cortical blindness after heart surgery in a child patient: A case report / 대한마취과학회지

Visual loss occurring after pediatric cardiac surgery employing cardiopulmonary bypass (CPB) is relatively rare but the risk is substantial. Compromised cerebral perfusion due to a CPB related micro-embolization and inflammatory vascular changes as well as reduced oxygen carrying capacity in hemodilution and hypothermia during CPB might be major contributing factors to the development of postoperative visual loss after cardiac surgery with CPB. A case of immediate but transient postoperative visual loss was encountered in a 21-month-old male who underwent tricuspid valve surgery. Despite routine intraoperative measures to maintain an adequate perfusion pressure throughout the procedure, postoperative computed tomography revealed a subacute infarct in his occipital lobe. Recovery began on postoperative day 28, and the patient's vision was restored by 31 days.

Protective Effects of Gabapentin on Allodynia and alpha2delta1-Subunit of Voltage-dependent Calcium Channel in Spinal Nerve-Ligated Rats

This study was designed to determine whether early gabapentin treatment has a protective analgesic effect on neuropathic pain and compared its effect to the late treatment in a rat neuropathic model, and as the potential mechanism of protective action, the alpha2delta1-subunit of the voltage-dependent calcium channel (alpha2delta1-subunit) was evaluated in both sides of the L5 dorsal root ganglia (DRG). Neuropathic pain was induced in male Sprague-Dawley rats by a surgical ligation of left L5 nerve. For the early treatment group, rats were injected with gabapentin (100 mg/kg) intraperitoneally 15 min prior to surgery and then every 24 hr during postoperative day (POD) 1-4. For the late treatment group, the same dose of gabapentin was injected every 24 hr during POD 8-12. For the control group, L5 nerve was ligated but no gabapentin was administered. In the early treatment group, the development of allodynia was delayed up to POD 10, whereas allodynia was developed on POD 2 in the control and the late treatment group (p<0.05). The alpha2delta1-subunit was up-regulated in all groups, however, there was no difference in the level of the alpha2delta1-subunit among the three groups. These results suggest that early treatment with gabapentin offers some protection against neuropathic pain but it is unlikely that this action is mediated through modulation of the alpha2delta1-subunit in DRG.

Amiodarone Induced Toxic Hepatitis: A case report / 대한마취과학회지

Although amiodarone is a widely used and effective long-term antiarrhythmic drug, it is known to have life-threatening adverse effects, including acute hepatotoxicity. Although the occurrence of acute hepatotoxicity after amiodarone administration is rare, it can be fatal. However, this phenomenon has not been well studied. Here, we describe a 39 year old woman with atrial fibrillation and supraventricular tachycardia who developed acute toxic hepatitis within 8 days of amiodarone administration at the recommended dosage. The drug was withdrawn and the laboratory findings progressively returned to normal.

The Effect of Premedication using a Jet-injector in Pediatric Patients / 대한마취과학회지

BACKGROUND: This study was designed to evaluate the efficacy and safety of midazolam premedication administered by a jet-injector in pediatric patients. METHODS: Children undergoing outpatient surgery were randomized into three groups: intravenous induction with thiopental sodium (control group, n = 20), oral midazolam premedication (PO-med group, n = 20) or midazolam premedication using a jet-injector (Jet-med group, n = 20). In the PO-med and Jet-med group patients, anesthetic induction was performed by sevoflurane inhalation and an intravenous catheter (IVC) was inserted after the children had been anesthetized by sevoflurane inhalation. For the control group patients, an IVC was placed in the preoperative holding area. Agitation scores were recorded in the preoperative holding area and recovery room. Anesthesia times and the views of the medical staff concerning the technique benefits were also noted. Patients and parents were interviewed on the following day. RESULTS: Maximum agitation scores in the preoperative holding area and during separation with parents were significantly lower in the PO-med and Jet-med groups. The induction time was significantly longer in the PO-med and Jet-med groups. No statistically significant differences were found for the recovery characteristics. Though interviews with patients and parents produced similar results for patients in each group, the medical staff satisfaction levels were significantly higher for patients in the PO-med and Jet-med groups. CONCLUSIONS: The findings of this study suggest that the application of the jet-injector for midazolam premedication may be clinically useful in children who do not have an IVC. The use of the jet-injector could be a substitute for the oral route for midazolam administration.

Locked-jaw as a Result of an Unexpected Anatomic Variation of the Temporomandibular Joint: A case report / 대한마취과학회지

A 36-year-old woman with an unremarkable medical history presented for laparoscopic cholecystectomy. Routine preoperative assessment of the patient's airway revealed normal jaw opening. Upon induction of anesthesia, her jaw locked in a nearly closed position. X-ray and MRI of the temporomandibular joints that were taken postoperatively showed normal findings except for the steeper posterior angles of the articular eminences. During the next induction of anesthesia, intubation was readily accomplished by opening the mandible with a forward pulling of the chin.

Cardiac Arrest Occurred by Tension Pneumothorax during Right Thoracotomy: A case report / 대한마취과학회지

Tension pneumothorax during one-lung ventilation is an insidious, life threatening emergency. Even though early diagnosis and rapid intervention are necessary to prevent mortality, treatment may be difficult because of the clinical diagnosis-mediastinal shift, hypoxemia, hypotension and increased airway pressure may be confusing in the operative setting. We present here the case of a patient who underwent right thoracotomy with one-lung ventilation and the patient developed left tension pneumothorax with resulting cardiac arrest.

Bupivacaine-induced Apoptosis in the Primary Cultured Cardiomyocytes via p38 MAPKs / 대한마취과학회지

BACKGROUND: It is known that bupivacaine induce cell death in several immortalized cells. However, there is no report concerning bupivacaine-induced cell death in the primary cultured cardiomyocytes. We compared the direct cytotoxicity of local anesthetics in cardiomyocytes. Furthermore, the mechanisms of cell death were evaluated. METHODS: The myocardial cells of rat pups were cultured 3 days after seeding. The methyltetrazolium (MTT) assay was employed to quantify differences in cellular viability. To confirm apoptosis, Hoechst-propidium iodide staining, DNA fragmentation by electrophoresis and western blot analysis were performed. And to examine the mechanisms of cell death, intracellular calcium and expression levels of mitogen-activated protein kinases (MAPKs) family members were evaluated. RESULTS: Among the local anesthetics under 1 mM concentration for 18 h, only bupivacaine significantly decreased the MTT activity (P < 0.001). Bupivacaine induced cell death in a dose-responsive and time dependent manner. Cell death showed apoptotic characteristics, such as DNA fragmentation, chromatin condensation, decrease of precursor caspase-3 protein level, increased cleaved PARP, and cytochrome C release into the cytoplasm. Bupivacaine phosphorylated three major MAPKs, i.e. extracellular signal-regulated kinases (ERKs), p38 kinase and c-Jun N-terminal kinases (JNKs) stress-activated protein kinases. Administration of ERK inhibitor increase cell death, whereas inhibitors of p38 kinase and JNK decreased cell death (P < 0.05). In addition, the intracellular calcium level was approximately 4 times higher after the bupivacaine treatment (P < 0.001), which was inhibited by calcium chelators (P < 0.001). Calcium chelators inhibited expression of MAPKs. CONCLUSIONS: In bupivacaine-induced apoptosis in cardiomyocytes, intracellular calcium increase and MAPKs family plays important roles.

Effect of Ketamine on Apoptosis by Energy Deprivation in Astroglioma Cells using Flow Cytometry System

Apoptosis is a programmed, physiologic mode of cell death that plays an important role in tissue homeostasis. As for the central nervous system, ischemic insults can induce pathophysiologic cascade of apoptosis in neurophils. Impairment of astroctye functions during brain ischemia can critically influence neuron survival by neuronglia interactions. We aimed to elucidate the protective effect of ketamine on apoptosis by energy deprivation in astrocytes. Ischemic insults was induced with iodoacetate/ carbonylcyanide mchlorophenylhydrazone (IAA/CCCP) 1.5 mM/ 20 micrometer or 150 micrometer/2 micrometer for 1 hr in the HTB-15 and CRL-1690 astrocytoma cells. Then these cells were reperfused with normal media or ketamine (0.1 mM) containing media for 1 hr or 24 hr. FITC-annexin-V staining and propidium iodide binding were determined by using flow cytometry. Cell size and granularity were measured by forward and side light scattering properties of flow cytometry system, respectively. An addition of keta-mine during reperfusion increased the proportion of viable cells. Ketamine alleviated cell shrinkage and increased granularity during the early period, and ameliorated cell swelling during the late reperfusion period. Ketamine may have a valuable effect on amelioration of early and late apoptosis in the astrocytoma cells, even though the exact mechanism remains to be verified.

Ca2+/Calmodulin-Dependent and -Independent Mechanisms are Involved in Angiotension II-induced Contraction of Rat Aortic Smooth Muscle / 대한마취과학회지

BACKGROUND: Angiotensin II (Ang II) appears to play important roles in the pathogenesis of hypertension. However, the mechanism by which Ang II induces vascular smooth muscle contraction is not fully understood. The phosphorylation of myosin light chain (MLC) is an essential trigger of the cascade that initiates of smooth muscle contraction. In this study, we investigated the role of MLC phosphorylation on Ang II-induced vascular smooth muscle contraction. METHODS: Rat thoracic aortas were used as an experimental substrates. We measured isometric tension, myosin light chain phosphorylation, intracellular Ca2+ concentration, mitogen-activated protein kinase phosphorylation, and tyrosine phosphorylation. RESULTS: 100 nM Ang II increased smooth muscle contraction transiently in rat thoracic aorta. Ang II also increased intracellular Ca2+ and 20 kDa MLC phosphorylation. Pretreatment with 10microM verapamil and 30microM La3+ abolished the contraction developed at 30 seconds by Ang II, whereas pretreatment with 10microM verapamil and 30microM La3+ abolished the contraction and the intracellular Ca2+ increase induced at 2 minutes by Ang II. Moreover, pretreatment of 10microM verapamil, 30microM La3+ and 1microM thapsigargin abolished the contraction as well as intracellular Ca2+ increase developed at 30 seconds and 2 minutes by Ang II. However, MLC phosphorylation was not affected. GF109203X attenuated Ang II-induced contraction more so than ML-7. 100 nM Ang II increased tyrosine phosphorylation of mitogen-activated protein kinase, 68 and 125 kDa proteins. The 125 kDa protein was confirmed as paxillin in primary vascular smooth muscle cell culture. CONCLUSIONS: Ang II-induced contraction involves Ca2+-dependent and independent components, and Ca2+-dependent contraction by Ang II is mediated by voltage-dependent Ca2+ channel. Moreover, protein kinase C and the mitogen-activated protein kinase activation pathway are involved in Ang II-induced contraction.

The Newly Adopted Integrative Curriculum at Chungbuk National University Medical School / 한국의학교육

PURPOSE: Entering a new century in the year 2001, Chungbuk National University Medical School (CNUMS) decided to adopt a fully integrative curriculum. This plan has been executed from 2002 to 2005. we are now at a point to assess this new curriculum and further improve it for the future. METHODS: We studied 'Curricula for Undergraduate' from Chungbuk National University and 'The Present Educational Status of Medical College' the Dean's Council of Korean Medical College published from 1987 to 2005. RESULTS: All lectures consisted of integrated lectures between the basic and clinical medical sciences. First and second year lectures focused on the horizontal integration of basic and clinical medical sciences, respectively. Also lectures between the first and second years formed longitudinal integration and purposeful repetition. Practical Classes were comprised of essential major clinical medicines and elective clinical medicines. Generally, lectures were reduced to introduce active learning subjects including problem-based learning (PBL), communicational skills, objective structured clinical examination (OSCE) /clinical performance examination (CPX), basic clinical skills, community medicine, and health and society. CONCLUSION: The curriculum of CNUMS was changed from the traditional department-centered lectures to integrated organ-centered integrated lectures and practical classes. However, further innovation is required on the inside of curriculum.

Hyperventilation Attack during Recovery from General Anesthesia: A case report / 대한마취과학회지

A hyperventilation attack is common in people with overanxiety and nervous prostration. However, persistent hyperventilation can cause many severe complications. Although there have been many case reports and studies on the hyperventilation attack, there has been no case report that occured during the recovery from general anesthesia. We experienced a unique case of hyperventilation attack during recovery from general anesthesia. The patient was a previously healthy 18 years old female who did not have any other history of hyperventilation or psychogenic problems. During general anesthesia recovery, she suddenly hyperventilated (respiratory rates>50/min). This hyperventilation waxed and waned in proportion to the sedation by the target- controlled infusion with propofol. The respiratory rates were stabilized to below 20/minute in 5 hours later.

Correlation of AEP, BIS and OAA/S Scores Under Stepwise Sedation Using Propofol TCI in Orthopedic Patients Undergoing Total Knee Replacement Arthroplasty Under Spinal Anesthesia / 대한마취과학회지

BACKGROUND: We performed a prospective, randomized study to investigate the relations between BIS (bispectral index, BISTM monitor), AAI (mid-latency AEP, A-line ARX index) and depth of sedation, and assessed two different memory functions at OAA/S score 2 under spinal anesthesia. METHODS: 44 ASA physical status 1-2 patients, scheduled for elective total knee replacement arthroplasty were randomly allocated to either the BIS group (22) or the AEP group (22). Under spinal anesthesia, patients were sedated with propofol TCI to OAA/S score 2. BIS and AAI at each OAA/S score were measured and patients were maintained at an OAA/S score 2. A specific picture was shown during the operation. At PACU, an interview was done to determine whether patients recalled specific picture (picture recall) or any intra-operative noises or scenes (op recall). RESULTS: BIS decreased as OAA/S score reduced from 5 to 2 (P < 0.05), but AAI could not differentiate between an OAA/S score 3 and 2 (P = 0.0690). There were correlations of 0.827 and 0.610, respectively, (Spearman's rho) between BIS and OAA/S scores and between AAI and OAA/S scores. BIS was higher at all OAA/S scores (P < 0.05), and the standard deviations of BIS were smaller. There was a statistically significant difference between the recalls (P = 0.0253). CONCLUSIONS: Both BIS and AAI provided information about the depth of sedation, but BIS was more accurate. The difference between 'op recall' and 'picture recall' requires further investigation.

The Influence of Sevoflurane on the Autonomic Nervous System / 대한마취과학회지

BACKGROUND: Sevoflurane is a new inhalation anesthetic, which shows stable hemodynamic features, and does not have a pungent odor, so that it can be used as an inhalational induction agent. But mask ventilation can make patients anxious, and can stimulate the sympathetic nervous system. Therefore, we evaluated the effect of midazolam administered right before inhalation induction with sevoflurane on the autonomic nervous system using power spectral analysis. METHODS: We studied 28 patients undergoing elective surgery. They were assigned to one of two groups to receive either sevoflurane with midazloam (M group) or sevoflurane alone (S group). Anesthesia was induced with 6% sevoflurane and 0.03 mg/kg midazolam or 6% sevoflurane alone. Midazolam was administered immediately before induction with sevoflurane. An electrocardiogram was applied to all patients and connected to a computer, for power spectral analysis. Power values were recorded on arrival, pre-intubation, post-intubation and pre-incision, and compared between two groups. RESULTS: Power values at low frequency were lower, and the time to loss of eye lash reflex and induction were shorter in the M group than in the S group. CONCLUSIONS: The administration of midazolam before induction with sevoflurane reduced the activity of the sympathetic nervous system versus induction with sevoflurane alone.

A Case of Transient Myeloproliferative Disorder with Down Syndrome, Presented Hepatosplenomegaly on Prenatal Sonography

Down syndrome (DS) is associated with a higher incidence of leukemia than general population; the subtype is acute megakaryoblastic leukemia (AMKL) in 50% of cases. DS is also strongly associated with transient myeloproliferative disorder (TMD), which is usually diagnosed during newborns and infants. Due to its difficulty in distinguishing TMD from acute leukemia (AL), the diagnosis of TMD should be made with extreme caution. Unlike AL, most cases of TMD resolve spontaneously within 3 months; blast cells disappear within 8 weeks in 80% and within 10 weeks in 90% of the surviving patients. Some infants with TMD, however, may have a severe complication leading into life-threatening clinical course with hepatosplenomegaly, lymphadenopathy, liver impairment, respiratory distress, anemia, infection and hemorrhage. Rarely, AL can develop after remission of TMD. We report a case of TMD with DS in newly born infant who presented hepatosplenomegaly on prenatal sonography and improved with exchange transfusion, steroid.

The Effect of Intravenous Ketamine on Recovery from Total Intravenous Anesthesia with Propofol / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the effects of the continuous infusion of ketamine on recovery characteristics after total intravenous anesthesia (TIVA) with propofol. METHODS: Fifty-six patients undergoing tympanoplasty were randomly allocated to group I (control, n = 20), group II (ketamine 0.3 microgram/ml, n = 16) or group III (ketamine 0.6 microgram/ml, n = 20). Ketamine and propofol were continuously administered by using target-controlled infusion (TCI) at different ketamine steady-state concentrations. Blood pressure, heart rate and the time interval from the discontinuation of propofol to eye opening and discharge were measured. RESULTS: The changes in mean arterial pressure and heart rate before and after auditory ossicles movement examination were larger in group I than in group II or in group III (P <0.05). And, the times to eye opening and to discharge from the recovery room were longer in group II and group III than in group I (P <0.05). Hallucination occurred only in seven patients of group III. CONCLUSIONS: Groups II and III were more stable hemodynamically than group I, but patients in groups II and III required a longer recovery time than group I. No hallucination was found in groups I and II. We conclude that when ketamine is administered in combination with propofol, a lesser concentration than 0.3 microgram/ml of ketamine or early discontinuation of ketamine infusion appear to be appropriate.

Effects of Rocuronium on Smooth Muscle Tension of Isolated Rat Thoracic Aorta / 대한마취과학회지

BACKGROUND: The cardiovascular effects of muscle relaxants may be produced by a muscarinic receptor block, ganglion block, increased noradrenaline release and blockage of it's reuptake or histamine liberation. However certain analogues of steroidal muscle relaxants directly cause relaxation of isolated vascular smooth muscles. Rocuronium is the 2-morpholino, 3-desacetyl, 16-N-allyl-pyrrolidino derivative of vecuronium, known to have a relative lack of ganglion blocking, sympathomimetic effects or histamine release. The aim of this study was to investigate the effect and action mechanism of rocuronium on isolated aortic smooth muscle in rats. METHODS: The ability of rocuronium to elicit a direct relaxant effect on vascular smooth muscle has been studied using isolated rat thoracic aortic rings contracted with phenylephrine (PE). Each ring of aortic arteries was suspended on wire supports in a 20 ml tissue bath under 2 g of resting tension. All tissues were bathed in Tris Tyrode solution at 37degrees C and 100% oxygen was supplied. RESULTS: Rocuronium 10(-4) M and 10(-2) M shifted the cumulative concentration-effect curves of PE to the right significantly (P<0.05). This relaxation effect of the aortic rings was not reversed with L-NAME or methylene blue pretreatment. However indomethacine shifted this curve to the right, and intracellular calcium release and extracellular calcium influx decreased significantly (P<0.05). CONCLUSIONS: From the results obtained with this experiment, it is concluded that the relaxation effects of rocuronium is not endothelium dependent and in part, is related with cyclooxygenase inhibition. Rocuronium inhibited intracelluar calcium release and extracelluar calcium influx.