An Anthranilate Derivative Inhibits Glutamate Release and Glutamate Excitotoxicity in Rats.

The neurotransmitter glutamate plays an essential role in excitatory neurotransmission; however, excessive amounts of glutamate lead to excitotoxicity, which is the most common pathogenic feature of numerous brain disorders. This study aimed to investigate the role of butyl 2-[2-(2-fluorophenyl)acetamido]benzoate (HFP034), a synthesized anthranilate derivative, in the central glutamatergic system. We used rat cerebro-cortical synaptosomes to examine the effect of HFP034 on glutamate release. In addition, we used a rat model of kainic acid (KA)-induced glutamate excitotoxicity to evaluate the neuroprotective potential of HFP034. We showed that HFP034 inhibits 4-aminopyridine (4-AP)-induced glutamate release from synaptosomes, and this inhibition was absent in the absence of extracellular calcium. HFP034-mediated inhibition of glutamate release was associated with decreased 4-AP-evoked Ca2+ level elevation and had no effect on synaptosomal membrane potential. The inhibitory effect of HFP034 on evoked glutamate release was suppressed by blocking P/Q-type Ca2+ channels and protein kinase C (PKC). Furthermore, HFP034 inhibited the phosphorylation of PKC and its substrate, myristoylated alanine-rich C kinase substrate (MARCKS) in synaptosomes. We also observed that HFP034 pretreatment reduced neuronal death, glutamate concentration, glial activation, and the levels of endoplasmic reticulum stress-related proteins, calpains, glucose-regulated protein 78 (GRP 78), C/EBP homologous protein (CHOP), and caspase-12 in the hippocampus of KA-injected rats. We conclude that HFP034 is a neuroprotective agent that prevents glutamate excitotoxicity, and we suggest that this effect involves inhibition of presynaptic glutamate release through the suppression of P/Q-type Ca2+ channels and PKC/MARCKS pathways.

Evaluation of tracheal intubation: A retrospective study of skill acquisition by medical students in the operating theater.

BACKGROUND/PURPOSE: Tracheal intubation is a critical life-saving invasive procedure. Medical students generally obtain the skill of performing tracheal intubation in the operating theater during their anesthesiology rotation. In this study, we sought to characterize medical students' skill acquisition of tracheal intubation. METHODS: We retrospectively reviewed the logbooks of 94 medical students who had completed a 3-4 week rotation in our department between January 2011 and June 2012. RESULTS: Ninety-four students performed 934 tracheal intubations. The success rate of intubation was 76.7%. After adjustment for age, body mass index, Mallampati class and grade, American Society of Anesthesiology (ASA) scores, and surgical category, the odds ratio of successful tracheal intubation improved with cumulative practice [odds ratio (OR) = 1.05 for each additional intubation performed; 95% confidence interval (CI) 1.00-1.09]. By contrast, the success rate decreased significantly with increasing scores of Mallampati class (OR = 0.32 for each increase in class; 95% CI 0.23-0.24) and grade (OR = 0.57 for each increase in grade; 95% CI 0.39-0.84). The main reason for intubation failure (57%) was poor visualization of vocal cords, due to suboptimal placement of the position of the laryngoscope. The satisfaction and confidence of students regarding the ability of performing tracheal intubation increased with each additional procedure, but decreased significantly after multiple unsuccessful attempts and the occurrence of any complication. CONCLUSION: Medical students acquired the ability of tracheal intubation and overcame major challenges through cumulative clinical practice of the procedure.

New 6% hydroxyethyl starch 130/0.4 does not increase blood loss during major abdominal surgery - a randomized, controlled trial.

BACKGROUND/PURPOSE: Ideal fluid management during surgery still poses a clinical dilemma gauging the benefits and adverse effects. This randomized controlled trial compared the tissue perfusion and coagulation profiles under clinically equivalent hydroxyethyl starch (HES 130/0.4) and lactated Ringer's solution (LR). METHODS: Eighty-four patients undergoing major abdominal surgery were randomized to receive either HES or LR. Tissue perfusion parameters using heart rate, arterial blood pressure, central venous pressure, cardiac index, stroke volume index, and central venous oxygen saturation were measured at T0 (baseline), T1 (start of surgery), T2 (1 hour after start of surgery), and T3 (end of surgery). Coagulation parameters using thrombelastography (TEG) were measured at T0 (baseline), T4 (after 15 mL/kg fluid transfused), and T5 (24 hours after baseline). RESULTS: The total amount of fluid administrated was 1547.9 ± 424.0 mL in HES group and 2303.1 ± 1033.7 mL in LR group (p < 0.001). The parameters of tissue perfusion and TEG did not differ significantly between groups at any time point except for a transient decrease in clot kinetic and clot strength at T4 for HES group. There was no significant difference in blood loss and consumption of blood products between the two fluids. CONCLUSION: HES 130/0.4 is a more efficient intravascular volume expander to maintain tissue perfusion than conventional crystalloid. Transient hypocoagulability induced by HES 130/0.4 does not warrant excessive blood loss and blood transfusion.

Polymorphism of µ-Opioid Receptor Gene (OPRM1:c.118A>G) Might Not Protect against or Enhance Morphine-Induced Nausea or Vomiting.

A cohort, double blind, and randomized study was conducted to investigate the effect of a single nucleotide polymorphism of the µ-opioid receptor at nucleotide position 118 (OPRM1:c.118A>G) on the association with the most common side effects (nausea or vomiting) induced by intravenous patient control analgesia (IVPCA) with morphine, including incidence and severity analysis. A total of 129 Taiwanese women undergoing gynecology surgery received IVPCA with pure morphine for postoperative pain relief. Blood samples were collected and sequenced with high resolution melting analysis to detect three different genotypes of OPRM1 (AA, AG, and GG). All candidates 24 h postoperatively will be interviewed to record the clinical phenotype with subjective complaints and objective observations. The genotyping after laboratory analysis showed that 56 women (43.4%) were AA, 57 (44.2%) were AG, and 16 (12.4%) were GG. The distribution of genotype did not violate Hardy-Weinberg equilibrium test. There was no significant difference neither between the severity and incidence of IVPCA morphine-induced side effects and genotype nor between the association between morphine consumption versus genotype. However, there was significant difference of the relation between morphine consumption and the severity and incidence of IVPCA morphine-induced nausea and vomiting. The genetic analysis for the severity and incidence of IVPCA morphine-induced nausea or vomiting showed no association between phenotype and genotype. It might imply that OPRM1:c.118A>G does not protect against IVPCA morphine-induced nausea or vomiting.

Sex differences in conscious sedation during upper gastrointestinal panendoscopic examination.

BACKGROUND/PURPOSE: Sex differences in response to noxious stimuli or analgesia have been demonstrated. We investigated sex differences in conscious sedation during upper gastrointestinal panendoscopic examination with regard to drug dose and entropy scores. METHODS: We investigated sex differences in 30 men and 30 women who were undergoing conscious sedation during upper gastrointestinal panendoscopic examination. The drug mixture was prepared as 5 mg midazolam plus 1 mg alfentanil diluted with normal saline to a volume of 10 mL. An initial injection of 4 mL was followed by an additional 1 mL every 1 minute, until the modified Observer Assessment of Alertness and Sedation (OAAS) rating scale was ≤ 3 when the panendoscope was inserted. Further injection was allowed thereafter. Entropy values, including state entropy (SE) and response entropy (RE), were monitored from baseline to full recovery. RESULTS: The volume of mixture needed to achieve an OAAS score of ≤ 3 was significantly lower in men than in women (4.4 ± 0.7 mL vs. 4.8 ± 0.8 mL, p = 0.034). The initial drug demand was not significantly influenced by age, body weight, or body height. The RE and SE values at the time of panendoscope insertion were not significantly different between men and women. The total volume for men was also significantly lower than that for women (5.7 ± 1.1 mL vs. 6.5 ± 1.4 mL, p < 0.01). The lowest RE and SE values during the procedure were not significantly different between men and women. CONCLUSION: Women need more analgesic agents than men during panendoscopic examination. There was no significant difference between men and women with regard to anesthetic depth and response to noxious stimuli, as revealed by similar SE and RE values.

Patient -controlled epidural ropivacaine as a post-Cesarean analgesia: a comparison with epidural morphine.

OBJECTIVE: Conventional, intermittent, epidural morphine is widely applied as a post-Cesarean delivery analgesia. We compared the analgesic efficacy, motor weakness, and side effects of administering a patient-controlled epidural analgesia (PCEA) of pure ropivacaine versus the intermittent administration of epidural morphine after Cesarean delivery. MATERIALS AND METHODS: This randomized, double-blind study included 120 full-term parturients who underwent elective Cesarean delivery and received either PCEA with pure ropivacaine or an intermittent bolus epidural of 2 mg/10 mL morphine in normal saline twice per day. The efficacy of pain relief, post-Cesarean side effects, motor blockades, time to first ambulation, and global satisfaction scores were evaluated. RESULTS: Pain scores were recorded at the four evaluation times (2, 12, 24, and 48 hours post-Cesarean delivery), and the time to first ambulation did not statistically differ between the two groups. Patients in the ropivacaine group experienced more motor weakness at 2 and 12 hours, fewer side effects, and higher global satisfaction scores than those in the morphine group (p < 0.05). CONCLUSION: The analgesic efficacy after cesarean delivery was almost equivalent between two groups. PCEA with pure ropivacaine induced significant motor blockade during the first 12 hours, but without delaying the time to first ambulation. Patients in the ropivacaine group reported higher patient satisfaction scores due to the significant reduction of annoying side effects, such as pruritus, nausea, vomiting, and urinary retention.

Optimizing epidural fentanyl loading dose for early labor pain.

OBJECTIVE: Sufficient sensory blockade between L1 and T10 is required to relieve visceral pain during early labor. We examined whether the addition of fentanyl to a loading dose of 0.0625% bupivacaine could provide dose-dependent analgesic effects on early-stage labor pain. METHODS: Sixty parturients who requested epidural analgesia for labor pain were enrolled and randomly allocated to one of three groups. Group A (n = 20) received 10 mL of 0.0625% epidural bupivacaine as a loading dose alone. Group B (n = 20) received the same bupivacaine loading dose in combination with 2 microg/mL fentanyl. Group C (n = 20) received the same loading bupivacaine dose plus 4 microg/mL fentanyl. All patients received diluted bupivacaine plus 2 microg/mL fentanyl at a rate of 10 mL/hr as a maintenance dose. Fifteen minutes later, we recorded the highest cephalic and lowest caudal anesthetized dermatomes, side effects, and the number of patients who asked for supplemental analgesia. RESULTS: The highest anesthetized cephalic dermatome was at the level of T12 (T9-L1) in Group A, T9 (T8-T12) in Group B and T7 (T5-T9) in Group C (p < 0.05 among the three groups). Eleven patients (55%) requested supplemental bupivacaine for inadequate analgesia in Group A, six in Group B (30%), and none in Group C (0%). Pruritus was reported by seven (35%) patients in Group B and eight (40%) patients in Group C, but none in Group A. CONCLUSION: The addition of fentanyl to epidural bupivacaine dose-dependently increased the analgesic effect and higher loading doses of fentanyl increased the dermatomic coverage. We suggest that 0.0625% bupivacaine plus 4 microg/mL fentanyl is the ideal loading dose to provide the greatest segmental analgesia for early labor pain with minimal side effects.

Combination of low-dose nalbuphine and morphine in patient-controlled analgesia decreases incidence of opioid-related side effects.

BACKGROUND/PURPOSE: The addition of ultra-low-dose naloxone to patient-controlled analgesia (PCA) with morphine reduces opioid-related side effects. Nalbuphine, a mixed opioid agonist-antagonist, may be able to attenuate opioid-related side effects. The goal of the present study was to investigate the effect of combined low-dose nalbuphine and morphine in PCA for postoperative pain control after gynecological surgery. METHODS: This randomized, double-blind, controlled study enrolled 174 female patients who were undergoing total abdominal hysterectomy, myomectomy, or ovarian tumor excision. In the control group, the PCA formula was 1 mg/mL pure morphine. In the study group, the PCA formula was 1 mg/mL morphine and 10 microg/mL nalbuphine (1:100). Numerical rating score, PCA requirement, nausea, vomiting, use of antiemetics, pruritus, use of antipruritics, and opioid-related adverse events were investigated at 1, 2, 4, and 24 hours postoperatively. RESULTS: One hundred and sixty-nine patients completed the study: 86 in the control group and 83 in the study group. The incidence of nausea was lower in the study group (41%) than in the control group (65%). The incidence of vomiting, use of antiemetics, pruritus, and use of antipruritics did not differ between the two groups. The numerical rating pain score and PCA requirements were not significantly different between the two groups. CONCLUSION: Combination of low-dose nalbuphine and morphine in PCA decreases the incidence of opioid-related nausea, without affecting the analgesia and PCA requirement. This novel combination can improve the quality of PCA used for postoperative pain control after gynecological surgery.

Propofol attenuates the decrease of dynamic compliance and water content in the lung by decreasing oxidative radicals released from the reperfused liver.

BACKGROUND: Remote pulmonary injuries after hepatic reperfusion are frequently caused by reactive oxygen species (ROS)-induced damage. The choice of anesthetics may affect the balance between oxidants and antioxidants, and propofol, a commonly used anesthetic, has an antioxidant effect. In this study, we developed a model to study pulmonary function with hepatic ischemia/reperfusion (I/R) manipulation, with the aim of defining remote pulmonary dysfunction after hepatic reperfusion and determining if propofol affects this dysfunction by altering ROS production from the liver or lungs. METHODS: Adult male rats weighing 160-250 g were randomly divided into four groups according to the type of surgery (sham or I/R) and the anesthetic administered (pentobarbital or propofol). To induce I/R, the portal vein and hepatic artery to the left and medial lobes of the liver were clamped. All of the measurements were done after 5 h of reperfusion, after 45 min of ischemia. Pulmonary function after hepatic I/R was determined by dynamic compliance, resistance and wet-to-dry ratio, and by histopathology. Hepato-cellular injuries were confirmed by alanine aminotransferase, whereas ROS production was measured from the inferior vena cava, jugular vein, and carotid artery. Products of lipid peroxidation, thiobarbiturate acid reactive substances and malondialdehyde, were measured in lung and hepatic tissues. RESULTS: Remote lung injury after hepatic I/R was shown by a significant decrease of Cdyn, and increases in resistance and the wet-to-dry ratio. ROS production was significantly increased and was highest in samples from the inferior vena cava. Thiobarbiturate acid reactive substances and malondialdehyde in the liver and serum alanine aminotransferase were significantly increased only in the I/R+pentobarbital group. All of the changes were significantly attenuated in the I/R+ propofol group (P=0.05). With propofol infusion, there was decreased ROS production from the reperfused liver, with less hepato-cellular injury, followed by well-maintained pulmonary function. CONCLUSION: Remote pulmonary dysfunction and reperfusion injury in the liver were demonstrated in our rat model, as well as massive ROS production and lipid peroxidation. Propofol infusion attenuated remote pulmonary injury by lessening oxidative injury from the reperfused liver.

Analgesic effect of lidocaine patch 5% in the treatment of acute herpes zoster: a double-blind and vehicle-controlled study.

BACKGROUND AND OBJECTIVES: Although lidocaine patch 5% has been widely used for postherpetic neuralgia, its analgesic effect on the intense pain associated with acute herpes zoster has not been investigated because of its potential hazard to damaged skin. METHODS: Forty-six patients suffering from moderate to severe pain caused by acute herpes zoster infection (within 4 weeks of onset) were enrolled in a randomized, double-blind, vehicle-controlled, parallel study. Lidocaine patch 5% or vehicle patch were applied to the intact portion of the painful skin area without blisters at 12-hour intervals twice a day for 2 consecutive days. Analgesic efficacy and side effect profiles were assessed before and 48 hours after patch application. RESULTS: We found that both groups of patients experienced significant pain relief during rest and movement. Differences of mean reduction of pain intensity between the two groups were 14.7 (4.7-24.8, P = 0.005) during rest and 10.4 (1.6-19.3, P = 0.007) during movement, favoring the lidocaine patch. The lidocaine patch produced a greater percentage change in a patient's global impression than the vehicle patch. The incidence and severity of adverse events were low with both treatments. CONCLUSIONS: This study demonstrates that lidocaine patch 5%, applied twice a day, could serve as a well tolerated and effective modality to relieve moderate to severe pain associated with acute herpes zoster presumably through its pharmacological action and physical barrier effect on sensitized skin.

Effect of combining ultralow-dose naloxone with morphine in intravenous patient-controlled analgesia: the cut-off ratio of naloxone to morphine for antiemesis after gynecologic surgery.

BACKGROUND/PURPOSE: Admixing an ultralow dose of naloxone with intravenous morphine patient-controlled analgesia (PCA) has been shown to decrease postoperative nausea. However, the cut-off ratio of the naloxone-morphine admixture for antiemetic effects has not been investigated. The purpose of this study was to investigate the cut-off ratio of naloxone-morphine admixture in PCA for antiemesis after gynecologic surgery. METHODS: This double-blind study enrolled 120 female patients who were scheduled for gynecologic surgery under general anesthesia. Patients were randomly allocated to one of three groups (n = 40 for each group). The concentration of naloxone and morphine respectively was 0 microg/mL and 1 mg/mL in group 1, 0.1 microg/mL and 1 mg/mL in group 2 (1:10,000), and 1 microg/mL and 1 mg/mL in group 3 (1:1000). Morphine consumption, verbal rating score of wound pain at rest and with exertion, and morphine-related side effects were investigated at 1, 2, 4 and 24 hours postoperatively. RESULTS: A total of 112 patients completed the study (37 in group 1, 36 in group 2, 39 in group 3). The incidence of nausea during the postoperative 4-24 hours was significantly lower in group 3 than in group 1 (23.1% vs. 56.8%, p < 0.05). Furthermore, the overall incidence of severe nausea was significantly lower in group 3 than in group 1 (2.6% vs. 24.3%, p < 0.05) as was the rescue antiemetic requirements (5.1% vs. 24.3%, p < 0.05). However, there were no significant differences between groups 2 and 1. The pain scores (at rest and with exertion) and 24-hour morphine consumption were not significantly different among the three groups. CONCLUSION: The antiemetic efficacy of ultralow-dose naloxone combined with PCA morphine is limited by a cut-off ratio of naloxone to morphine of 1:10,000.

Effective epidural blood patch volumes for postdural puncture headache in Taiwanese women.

BACKGROUND/PURPOSE: Epidural blood patch (EDBP) is the most commonly used method to treat postdural puncture headache (PDPH). The optimal or effective blood volume for epidural injection is still controversial and under debated. This study compared the therapeutic efficacy of 7.5 mL blood vs. 15 mL blood for EDBP via epidural catheter injection. METHODS: Thirty-three patients who suffered from severe PDPH due to accidental dural puncture during epidural anesthesia for cesarean section or epidural analgesia for labor pain control were randomly allocated into two groups. EDBP was conducted and autologous blood 7.5 mL or 15 mL was injected via an epidural catheter in the semi-sitting position in Group I (n = 17) and II (n = 16), respectively. For all patients in both groups, the severity of PDPH was registered on a 4-point scale (none, mild, moderate, severe) and assessed 1 hour, 24 hours and 3 days after EDBP. RESULTS: There was no significant difference between the two groups of patients at all time points with respect to the severity of PDPH. Two patients in Group I and nine in Group II developed nerve root irritating pain during blood injection (p < 0.05). No systemic complications were noted in both groups of patients throughout EDBP injection. CONCLUSION: We conclude that injection of 7.5 mL autologous blood into the epidural space is comparable to 15 mL blood in its analgesic effect on PDPH, but with less nerve root irritating pain during injection.

Oxidative stress during 1-lung ventilation.

OBJECTIVES: Resuming 2-lung ventilation from 1-lung ventilation might induce a re-expansion and reoxygenation effect. The oxidative stress during 1-lung ventilation/2-lung ventilation has not been studied, although severe complications, such as re-expansion pulmonary edema, were reported. Reactive oxygen species production and total antioxidant status assay levels were measured in this study during 1-lung ventilation/2-lung ventilation. The effects on extravascular lung water, cardiac output, and intrathoracic blood volume were also studied by using the Pulsion PiCCO system. METHODS: Twenty patients undergoing 1-lung ventilation/2-lung ventilation (>60 minutes) for video-assisted thoracoscopic surgery with minimal lung injuries were included in this study. Reactive oxygen species production was measured by means of lucigenin (detecting superoxide mainly) and luminol (detecting H2O2 and HOCl mainly) chemiluminescence. Reactive oxygen species production, total antioxidant status assay (by using the Randox TAS kit), extravascular lung water, cardiac output, and intrathoracic blood volume values were measured before 1-lung ventilation (T1), before resuming 2-lung ventilation (T2), 5 minutes after 2-lung ventilation (T3), and 30 minutes after 2-lung ventilation (T4). RESULTS: One-lung ventilation time was 118 +/- 33 minutes. Lucigenin chemiluminescence (but not luminol chemiluminescence) increased significantly at T3 and T4. Total antioxidant status decreased nonsignificantly. Extravascular lung water, intrathoracic blood volume, and permeability index values changed nonsignificantly after 2-lung ventilation. Cardiac output increased significantly at T4, and there is a negative correlation between cardiac output and extravascular lung water (r = -0.431, P < .005). CONCLUSIONS: Resuming 2-lung ventilation induces a massive superoxide production. Comparable extravascular lung water and intrathoracic blood volume and a nonsignificant decrease of total antioxidant status indicate adequate antioxidant capacity to counteract it. Severe oxidative injuries after 1-lung ventilation/2-lung ventilation should be considered in patients without adequate antioxidative capacity, such as those with cancer and trauma.

The optimal injection time of alfentanil for blunting circulatory responses to tracheal intubation.

BACKGROUND: The aim of this study is to investigate the optimal injection time of alfentanil during induction of anesthesia to blunt the circulatory responses induced by laryngoscopy and tracheal intubation. METHODS: Seventy-five patients of ASA class I or II were randomly assigned to five groups. Group I was the placebo group in which the patients received normal saline 2 ml just before induction. Patients in groups II, III, IV and V received alfentanil 10 microg/kg at 5, 3, 1 and 0.5 min before intubation respectively. Anesthesia was maintained with 1.5% isoflurane and nitrous oxide in 50% oxygen (2:2 L/min). The patients' heart rate and blood pressure before and after intubation were documented and compared. The occurrence of adverse effects was also recorded. RESULTS: Patients' demographic data, baseline hemodynamic profile and the laryngoscopic time did not differ among the five groups. The patients in groups II, III and IV showed decreased heart rate compared with group I within 3 min after intubation. The patients in group V like those in group I did not show a reduction in heart rate 1 min after intubation. The patients in groups II, III, IV and V all showed reduced systolic blood pressure and rate-pressure product (RPP) 2 min after intubation. The occurrence of hypotension and bradycardia was not different among the five groups; hypertension and high RPP were less in groups II, III and IV as compared with group I. Ninety-three percent patients in group II and group III suffered from dizziness after alfentanil administration. One patient in group II had nausea and another one patient displayed hypoxemia after alfentanil administration. CONCLUSIONS: Considering equal effectiveness and fewer side effects, one minute before intubation is the optimal injection time of alfentanil to blunt the circulatory responses induced by laryngoscopy and tracheal intubation.

Intravenous lidocaine and ephedrine, but not propofol, suppress fentanyl-induced cough.

PURPOSE: The aim of this study was to evaluate the effectiveness of lidocaine, propofol and ephedrine in suppressing fentanyl-induced cough. METHODS: One hundred and eighteen patients were randomly assigned into four groups and the following medications were given intravenously: patients in Group I (n = 31) received normal saline 2 mL, Group II (n = 29) received lidocaine 2 mg.kg(-1), Group III (n = 30) received propofol 0.6 mg.kg(-1) and Group IV (n = 28) received ephedrine 5 mg. At one minute after the study medication, fentanyl 2.5 microg.kg(-1) was given intravenously within two seconds. The occurrence of cough and vital sign profiles were recorded within two minutes after fentanyl bolus by an anesthesiologist blinded to study design. RESULTS: Sixty-five percent of patients in the placebo group had cough, whereas the frequency was significantly decreased in Groups II (14%) and IV (21%). Although a numerically lower frequency of cough was noted in Group III (37%), it was not statistically different from that of the placebo group. SpO(2) decreased significantly in patients of Group III compared to placebo; one patient experienced hypoxemia necessitating mask ventilation. Patients in Group III showed a decrease in heart rate and systolic blood pressure (2 beats.min(-1) and 8 mmHg vs baseline). Patients in Group IV showed an increase in both measurements (5 beats.min(-1) and 8 mmHg vs baseline). No truncal rigidity was observed throughout the study. CONCLUSIONS: Intravenous lidocaine 2 mg.kg(-1) or ephedrine 5 mg, but not propofol 0.6 mg.kg(-1), was effective in preventing fentanyl-induced cough. The results provide a convenient method to decrease fentanyl-induced cough.

Differentiation of ketamine effects on renal nerve activity and renal blood flow in rats.

BACKGROUND: A biphasic pattern in the effects of increasing dose of ketamine on mean arterial blood pressure (MBP) and renal sympathetic nerve activities (RSNA) was shown in previous study. We hypothesized that if renal vascular resistance (RVR) and renal blood flow (RBF) are mainly controlled by RSNA, they will show a similar biphasic pattern under increasing doses of ketamine. METHODS: 16 female Wistar rats anesthetized with urethane were studied for ketamine at 0.5, 1, 2 mg/kg, i.v. at 30 min intervals. Multifiber RSNA recording was studied in 8 rats and RBF (by electromagnetic flowmeter) and RVR were studied in the other 8 rats with intact renal nerves. RESULTS: Our results showed that although incremental doses of ketamine brought about a biphasic pattern in MBP and RSNA, the decrease in RBF and the increase in RVR went a dose-related way. CONCLUSIONS: We concluded that there was a differentiation of ketamine effects on renal nerve activity and renal blood flow in rats. The changes of RBF and RVR can not only be attributed to the effects of sympathetic nerve activities.

General anesthetic management for diagnostic splenectomy in a patient with paraneoplastic pemphigus.

Paraneoplastic pemphigus (PNP) is an autoantibody-mediated mucocutaneous blistering disease that often occurs with confirmed or occult malignancy. It is often accompanied by extensive eruption of respiratory mucosa and can lead to respiratory failure. The indications for anesthetic management in patients with PNP are rare due to the high risk of generating further eruption of respiratory mucosa during intubation, with potentially disastrous consequences. We report the anesthetic management in a 43-year-old woman with PNP scheduled for diagnostic splenectomy. The surgery was postponed due to persistent hoarseness, diffuse oral-pharyngeal mucositis, and laryngeal erosion. Methylprednisolone 40 mg 3 times daily was prescribed for controlling the mucosa lesions. Two weeks later, after the improvement of mucosal lesions, direct laryngoscopic intubation and the scheduled splenectomy were performed under general anesthesia. Pathology of the spleen showed low-grade B-cell lymphoma had induced PNP. Flexible fiberoptic bronchoscopic examination revealed neither bleeding nor bullae formation in the trachea either immediately after intubation or before extubation. The tracheal mucosa is highly susceptible to mechanical stimulation with direct laryngoscopic intubation. Cuff inflation and positive pressure ventilation, awareness of the disease characteristics of PNP, a sufficient course of steroid therapy beforehand, and adequate mucosal protection are essential to the uneventful anesthetic management of the patient with PNP involving the respiratory tract mucosa.

Does the suggested lightwand bent length fit every patient? The relation between bent length and patient's thyroid prominence-to-mandibular angle distance.

BACKGROUND: To date, no study has explored the effect of bent length on lightwand intubation. For successful intubation in daily practice, the authors found that bent length should be approximated to the patient's thyroid prominence-to-mandibular angle distance (TMD), but some patients have a TMD much shorter than the suggested bent length range. The purposes of this study were to understand TMD distribution in adults and to test the influence of bent length on lightwand intubation. METHODS: The TMD, airway, and demographic data of 379 patients were collected. To test the bent length influence, patients were enrolled in group A (158 patients, TMD 5.5 cm) and were intubated randomly using the lower (6.5 cm) and upper (8.5 cm) limits of the suggested range. Success rate and lightwand search time were compared. RESULTS: In group A, the success rate was 98.8% with 6.5-cm bent length and 78.2% with 8.5-cm bent length (P < 0.05). Search times were 5.7 +/- 2.90 and 8.9 +/- 5.80 s with 6.5- and 8.5-cm bent length, respectively (P < 0.01). In group B, there was no statistical difference in success rate and search time between 6.5- and 8.5-cm bent length. CONCLUSION: The suggested range was suitable for patients in group B (TMD > 5.5 cm). However, in group A (