Fiberoptic bronchoscopic view change of laryngopharyngeal tissues by different airway supporting techniques: comparison of patients with and without open mouth limitation.

STUDY OBJECTIVE: To investigate the changes in view of the laryngopharyngeal tissues on the fiberoptic bronchoscope (FOB) with different techniques of supporting the airway. DESIGN: Prospective, observational, stratified study. SETTING: University hospital. PATIENTS: 40 ASA physical status I, II, and III men undergoing elective oromaxillofacial surgery during general anesthesia with nasotracheal intubation. INTERVENTIONS: Patients were allocated into the normal mouth-opening group (Group N) or the limited mouth-opening group (Group L) to determine the grade of view of the laryngopharyngeal tissues exposed on the FOB, with 5 different airway supporting techniques: original airway position (OA), triple airway (TA), jaw thrust with opened mouth (JTO), jaw thrust with teeth protrusion (JTP), and head tilt with chin lift (HT). MEASUREMENT AND MAIN RESULTS: An adequate airway support was defined as having nearly full visibility of the entire glottic inlet. The investigator graded the vision of both anterior and posterior laryngopharyngeal tissues of each patient. All subjects experienced adequate airway support with the TA and HT airway supporting techniques. The TA airway supporting technique significantly moved the posterior laryngeal tissues more upward in Group N than Group L (P = 0.027). The JTP airway supporting technique provided adequate airway support for 14 of the 20 patients in Group N but only for two of the 20 Group L patients (P < .001). CONCLUSION: Both the TA and HT techniques provided adequate airway support for patients with and without limited mouth opening.

Ultrasonographic examination to search out the optimal upper arm position for coracoid approach to infraclavicular brachial plexus block--a volunteer study.

BACKGROUND: Infraclavicular brachial plexus block has been widely used for surgical procedures below the mid humerus owing to its excellent anesthetic quality and ease of practice. However, what is the optimal upper arm position for carrying out the procedure still lacks consensus of opinion. The primary goal of this study was to determine the optimal upper arm position for coracoid infraclavicular block by ultrasonographic examination. METHODS: High-frequency (5-10 MHz) ultrasonographic examination on the vertical line 2 cm medial to the coracoid process was performed in 40 volunteers. We assessed the influence of four different upper arm positions on the topographic anatomy of the infraclavicular region. Ultrasonography-derived distances and morphometric measurements were applied to evaluate the optimal puncture site. The deviation of coracoid puncture site from the ultrasonographically modified ideal puncture site in distance was also recorded. RESULTS: When the upper arm was abducted 900, the brachial plexus was much closer to the skin (1.67 cm) and farther from the pleura (1.15 cm) as compared with other positions. In this position, the revealation of anterosuperior plexus relative to artery, identification of all three cords and pleura were 53.8%, 64.1% and 87.2%, respectively. We also found that as the upper arm was drawing from abduction to adduction the ideal puncture site tended to shift more inferiorly. CONCLUSIONS: We recommend the most optimal position for carrying out coracoid infraclavicular brachial plexus block is to abduct the upper arm 90 degrees with external rotation of the shoulder. Though ultrasonographic guidance is suggested for infraclaricular brachial plexus block, an optimal position for puncture site determined by anatomical landmark is also acceptable.

Age-related changes in oxytocin-, arginine vasopressin- and nitric oxide synthase-expressing neurons in the supraoptic nucleus of the rat.

Many histochemical investigations indicated that the oxytocin (OXY), the arginine vasopressin (AVP) and the nitric oxide synthase (NOS) have been synthesized in the supraoptic nucleus (SON) neurons. The objective of this study was to examine the age-related expression of the OXY, the AVP and the NOS in the SON of the young adult (2-month-old) and the aged (24-month-old) rats. The histochemistry for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d; marker for the NOS) and the double labeling histochemistry for the OXY/NADPH-d or the AVP/NADPH-d were employed, and the quantitative analysis was performed with a computer-assisted image processing system. In comparison of the young adult and the aged group, the cell number, the cell size and the reactive density of the NOS-expressing neurons showed a significant increase along with age, and these evidences suggested the age-related increase of the nitric oxide (NO) production. The age-related significant increase was not detected in the number of the OXY/NOS-expressing neurons in the dorsal part, but was detected in the number of the AVP/NOS-expressing neurons in the ventral part. Based on our histochemical findings and reports demonstrated by other authors, we attempted to discuss the physiological role of NOS for the secretion of posterior pituitary hormones along with age.

A xanthine-based epithelium-dependent airway relaxant KMUP-3 (7-[2-[4-(4-nitrobenzene)piperazinyl]ethyl]-1,3-dimethylxanthine) increases respiratory performance and protects against tumor necrosis factor-alpha-induced tracheal contraction, involving nitric oxide release and expression of cGMP and protein kinase G.

KMUP-3 (7-[2-[4-(4-nitrobenzene)piperazinyl]ethyl]-1,3-dimethylxanthine) was investigated in guinea pig tracheal smooth muscle. Intratracheal instillation of tumor necrosis factor (TNF)-alpha (0.01 mg/kg/300 microl) induced bronchoconstriction, increases of lung resistance, and decreases of dynamic lung compliance. Instillation of KMUP-3 (0.5-2.0 mg/kg) reversed this situation. In isolated trachea precontracted with carbachol, KMUP-3 (10-100 microM)-caused relaxations were attenuated by epithelium removal and by pretreatments with an inhibitor of K(+) channel, tetraethylammonium (10 mm); K(ATP) channel, glibenclamide (1 microM); voltage-dependent K(+) channel, 4-aminopyridine (100 microM); Ca(2+)-dependent K(+) channel, charybdotoxin (0.1 microM) or apamin (1 microM); soluble guanylate cyclase (sGC), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1one (ODQ, 1 microM); nitric-oxide (NO) synthase, N(omega)-nitro-L-arginine methyl ester (L-NAME, 100 microM); and adenylate cyclase, SQ 22536 [9-(terahydro-2-furanyl)-9H-purin-6-amine] (100 microM). KMUP-3 (0.01-100 microM) induced increases of cGMP and cAMP in primary culture of tracheal smooth muscle cells (TSMCs). The increase in cGMP by KMUP-3 was reduced by ODQ and L-NAME; the increase in cAMP was reduced by SQ 22536. Western blot analysis indicated that KMUP-3 (1 microM) induced expression of protein kinase A (PKA)(ri) and protein kinase G (PKG)(1alpha 1beta) in TSMCs.SQ 22536 inhibited KMUP-3-induced expression of (PKA)(ri). On the contrary, ODQ inhibited KMUP-3-induced expression of PKG(1alpha 1beta) In epithelium-intact trachea, KMUP-3 increased the NO release. Activation of sGC, NO release, and inhibition of phosphodiesterases in TSMCs by KMUP-3 may result in increases of intracellular cGMP and cAMP, which subsequently activate PKG and PKA, efflux of K(+) ion, and associated reduction in Ca(2+) influx in vitro, indicating the action mechanism to protect against TNF-alpha-induced airway dysfunction in vivo.

Comparison of the effect of two different doses of 0.75% glucose-free ropivacaine for spinal anesthesia for lower limb and lower abdominal surgery.

We compared the clinical efficacy and safety of two doses of ropivacaine for spinal anesthesia in Chinese patients undergoing lower limb and lower abdominal surgery. In this randomized, open-label study, 40 patients were divided into two groups: group A received 3.5 mL (26.25 mg) of 0.75% glucose-free ropivacaine, and group B received 4.5 mL (33.75 mg). Sensory and motor blocks were assessed during and after surgery through to complete recovery. Seven standard measurements were taken: time to onset of sensory blocks; maximum sensory cephalad spread; time to maximum sensory block; maximum number of blocked segments; duration of sensory block at L3; time to onset of complete motor block; and duration until complete motor block recovery. Vital signs and any adverse effects related to spinal anesthesia were also recorded. No significant differences were found between the two groups: time to onset of sensory block at L3 in group A vs B (2.1 +/- 9.6 vs 1.7 +/- 7.3 minutes), maximum cephalad spread [T4-5 (C3-T11) vs T4 (C3-T8)], maximum number of blocked segments (18.0 +/- 3.4 vs 19.8 +/- 3.7), time to maximum sensory block (34.0 +/- 22.9 vs 26.8 +/- 17.9 minutes), duration of sensory block at L3 (251.2 +/- 34.7 vs 277.3 +/- 51.1 minutes), time to onset of complete motor block (13.4 +/- 6.4 vs 10.3 +/- 3.4 minutes), and time for complete recovery from motor block (264 +/- 52.1 vs 292.5 +/- 64.5 minutes). No significant differences in global hemodynamic changes were found during and after the operation. While shivering was more frequent in group B during the operation, the difference was not significant. Otherwise, there were no differences in adverse effects during and after surgery. We conclude that both doses of 0.75% glucose-free ropivacaine, 26.25 mg (3.5 mL) and 33.75 mg (4.5 mL), have the same efficacy and safety in Chinese patients undergoing spinal anesthesia for lower limb and lower abdominal surgery.

Total intravenous anesthesia for repair of congenitral diaphragmatic hernia: a case report.

Congenital diaphragmatic hernia is a cardiopulmonary anomaly that causes severe respiratory disorder. Traditionally, inhalational anesthetics with mechanical hyperventilation, opioids, and muscle relaxants are used in anesthesia for repair surgery. In this case, we used total intravenous anesthesia combined with high-frequency oscillatory ventilation and inhaled nitric oxide for surgical repair of the diaphragm. After surgery, the patient recovered well and was discharged from hospital 1 month later.

Lightwand-assisted intubation of patients in the lateral decubitus position.

In some situations, patients need endotracheal intubation to maintain airway patency while they are constrained in the lateral position. In this study we compared lightwand-guided intubation of 120 randomly enrolled patients placed in the supine, right, or left lateral position. Group S patients were initially placed in the supine position, and subsequent to the artificial airway having been established they were turned to the lateral decubitus position. Group R patients were initially placed in a right decubitus position during induction and intubation. Group L patients were initially placed in a left decubitus position during induction and intubation. The duration of each intubation attempt, the total time to successful intubation, and the incidence of intubation-related intraoral injury, hemodynamic changes, and postoperative sore throat and hoarseness were recorded. Intubation took a similar length of time in the supine (14.5 +/- 13.4 s), left lateral (13.3 +/- 10.2 s), and right lateral positions (15.5 +/- 13.0 s) and resulted in a similar trend in hemodynamic changes. Patients in the lateral and supine positions revealed a comparable incidence of successful first-attempt intubation, sore throat, hoarseness, oral mucosal injury, and dysrhythmia. Insignificantly more esophageal intubations were performed in the lateral position in the first attempt at intubation; however, all patients were correctly intubated shortly after reattempting intubation. We concluded that lightwand-assisted intubation is easily performed and a similar technique may be used whether the patient is in a lateral, recumbent, or a supine position. This alternative technique should be practiced and is recommended for patients who must remain in a lateral position during intubation and surgery.

Accurate central venous port-A catheter placement: intravenous electrocardiography and surface landmark techniques compared by using transesophageal echocardiography.

UNLABELLED: Using transesophageal echocardiography (TEE) to locate the tip of central venous catheters inserted via the right subclavian vein, we compared IV electrocardiography (IV-ECG)-guided catheter tip placement with the conventional surface landmark technique. Sixty patients were randomly assigned into two groups. In Group E, the IV-ECG signal was conducted along an NaHCO(3)-filled catheter to facilitate catheter placement. In Group S, surface landmarks on the chest wall were used to determine the appropriate catheter length. The goal was to visualize the catheter tip with TEE at the superior edge of the crista terminalis, which is the junction of the superior vena cava (SVC) and right atrium (RA). The catheter tip position was considered to be satisfactory, as the tip was within 1.0 cm of the upper crista terminalis edge. All 30 Group E patients had satisfactory catheter tip placement when the ECG P wave was at its maximum. In contrast, 16 of the 30 patients in Group S had satisfactory tip positions (P < 0.001). All catheters were repositioned under TEE guidance to adjust the tip to the SVC-RA junction. After the catheter tips were confirmed to be located at the SVC-RA junction, the catheter tips were still visualized in the mid portion of RA in 12 of 60 patients on supine chest radiographs. We concluded that IV-ECG guidance to position a catheter resulted in satisfactory catheter tip placement that is in accordance with TEE views. Catheter placement at the SVC-RA junction with the surface landmark technique was unreliable. IMPLICATIONS: Intravenous electrocardiography guidance to position catheters obtains a satisfactory catheter tip placement that is in accordance with transesophageal echocardiography views. The surface landmark technique does not result in reliable placement at the superior vena cava-right atrium junction.

Spinal process landmark as a predicting factor for difficult epidural block: a prospective study in Taiwanese patients.

Although epidural anesthesia is a common practice in neuraxial blockade, difficult access to the epidural space is a frequent problem in operating theaters. We designed this study of epidural blocks to determine if the spinal landmark grading system is valuable in predicting a difficult epidural block. Before the epidural block, we collected the following data: demographics, body habitus (normal, thin, obese, pregnant), spinal anatomy (normal, deformed), spinal level (lumbar, thoracic), and spinal landmark grade (grade 1: spinous processes visible; grade 2: spinous processes not seen but easily palpated; grade 3: spinous processes not seen and not palpated but the interval between them is palpated as a low landmark under the thumb; grade 4: other). We performed all 848 epidural blocks initially using a midline approach and an 18-gauge Touhy needle. We evaluated the technical difficulty of the epidural block using three methods: whether the epidural block was accomplished at the spinal level (first-level success); the total number of attempts at skin puncture (attempts-S); and total number of attempts to change ligament puncture direction (attempts-L) required to complete the epidural block. Of all examined factors, spinal landmark grade correlated best with technical difficulty as measured by all three methods. Deformed spinal anatomy and body habitus both correlated with difficulty, merely from the total numbers of attempts (attempts-S and attempts-L). Thoracic epidurals were more difficult than lumbar epidurals by all three measures of difficulty. We concluded that this spinal landmark grading system is valuable in predicting a difficult epidural block and advocate its use as a predictor by anesthesiologists.

Ropivacane 0.1 % with or without fentanyl for epidural postoperative analgesia: a randomized, double-blind comparison.

Epidural analgesia is often considered optimal postoperative analgesia for certain surgical procedures. Ropivacaine is a new local anesthetic that is less toxic than its homologue, bupivacaine. Epidural infusions usually comprise a local anesthetic, an opioid, or a combination of the two to improve analgesic efficacy and reduce unwanted side effects. All 210 patients undergoing lower abdominal or lower extremity surgery received epidural analgesia infusions at 7 mL/hour, 105 with 0.1% ropivacaine and 105 with 0.1% ropivacaine plus 1 microg/mL fentanyl. Pain score and side effects (hypotension, nausea, vomiting, pruritus, paresthesia, urinary retention and motor block) were measured at 0, 0.5, 1, 3, 6, 12, and 24 hours. There was no statistical difference in patient profile between the groups. Pain relief scores were similar in the two groups in the first hour after the drugs were given. However, pain relief was significantly better in the ropivacaine/fentanyl group after the first hour and this difference lasted for the remaining time. There was no significant difference in adverse events between the two groups during 24 hours of assessment. In conclusion, the quality of analgesia was significantly improved by the addition of fentanyl 1 microg/mL to ropivacaine.

In vivo electroporation of proopiomelanocortin induces analgesia in a formalin-injection pain model in rats.

Opioids remain the most efficacious pharmacological agents for various clinical pain syndromes. Recently, various engineered cells capable of secreting opioidergic peptides have been applied to relieve pain in animal models. In vivo gene delivery by viruses encoding endogenous opioids has also been used with success. In this study, we attempted non-viral intrathecal in vivo gene delivery by electroporation to induce analgesia. Thirty Sprague-Dawley rats were used in this study, six in each of five groups. Rats were treated as follows: vehicle without electroporation (group A), vehicle with electroporation (group B), 100 microg of pCMV-hPOMC plasmid without electroporation (group C), or 100 microg of pCMV-hPOMC plasmid with electroporation (group D). Group E was treated with both pCMV-hPOMC plasmid and electroporation, and given naloxone (1mg/kg) 1h before the formalin test. The tail flick, paw withdrawal latency from radiant heat, and formalin test results for each groups were compared. Radioimmunoassay (RIA) and reverse transcription-polymerase chain reaction (RT-PCR) were used to determine the levels of expression of beta-endorphin in the spinal cord. beta-Endorphin expression was localized by immunohistochemistry. A significant decrease in the number of flinches in phase 2 of the formalin test was observed in the group treated with both plasmid and electroporation (group D), whereas the other measures of pain did not differ between groups. RIA and RT-PCR both showed increased expression of beta-endorphin in group D. The expression of beta-endorphin was highest in laminae I and II of the dorsal horn of the spinal cord. We conclude that electroporation successfully delivered intrathecally administered pCMV-hPOMC into the dorsal horn cells of the spinal cord, and induced analgesia in phase 2 of the formalin test in rats.

Epidural ropivacaine for postoperative analgesia in Taiwanese patients.

BACKGROUND: Ropivacaine is the latest long-acting amide local anesthetic. As it is less cardiovasculotoxic and neurotoxic than bupivacaine it is an attractive anesthetic agent used in clinical anesthesia and postoperative analgesia. This study was undertaken to seek for a suitable dosage of ropivacaine in postoperative analgesia for Taiwanese patients whose average physicality is not entirely compatible with the pharmacopeially recommended dosage for western people. METHODS: For assessment of epidural ropivacaine for postoperative analgesia 105 adult patients were enrolled and randomly allotted to three groups. Patients in Group A were given epidurally 0.15% ropivacaine, while those in Group B and Group C were given 0.125% and 0.10% ropivacaine respectively. Pain was evaluated with visual analogue scale (VAS) and modified Bromage scale, and adverse effects were recorded at the designated points of time during the postoperative 24-hour period. RESULTS: The demographic profiles were comparable among three groups. In VAS score, Group A (3.20 +/- 0.47) and B (3.11 +/- 0.41) did not differ much, while Group C (3.97 +/- 0.71) the score was signally higher than Group A and Group B (P < 0.05). Adverse effects, such as paraesthesia, nausea and urinary retention were observed more in Group A. CONCLUSIONS: From the results of this study, we are of the opinion that 0.125% ropivacaine could provide a postoperative analgesia in Taiwanese patients to their satisfaction with less adverse effects.

Reducing dust using the electrocautery pencil with suction combined with the infusion catheter in mastectomy.

The dust from the vaporized tissue released during a mastectomy presents a hazard to the patients and the operating room personnel. More dust has been noted using the conventional electrocautery pencil in dissecting breast tissue than with the metal knife used in the past. It is very important to reduce the hazardous dust released during mastectomy. For this study 80 patients undergoing mastectomy for breast cancer from March to June 2001 were divided into two groups: 1) those whose dissections were performed with a combination of an electrocautery pencil and suction with an intravenous infusion catheter (40 cases) and 2) those whose dissections were performed with the conventional method in which the electrocautery pencil was handled by the surgeon and the metal suction tube was used separately by an assistant (40 cases). During mastectomy the personal air sampler was affixed to the operator's neck to collect the dust from the vaporized tissue. The concentrations of the total dust were significantly lower in the combined electrocautery-suction method (mean 5.56 +/- 3.26 microg/m3) than in the conventional method (mean 34.81 +/- 4.83 microg/m3) during mastectomy (P < 0.05). Although the operating time and blood loss were less in the combined method than in the conventional method this difference was not statistically significant (P > 0.05). The combined method of using the electrocautery pencil for dissecting breast tissue along with the intravenous infusion catheter reduced the concentrations of the total dust from the vaporized tissue plume. Furthermore this method reduces the hazards of dust to the surgeons and operating room personnel. Additionally the cost of this combined method is lower than that of the conventional method.

The train of four ratio decreases to zero in anesthetized children is the guide to achieve a satisfactory intubation condition.

The purpose of this study is to investigate the satisfactory (excellent or good) intubation conditions attained when the TOF ratio was zero in anesthetized children. Sixty children undergoing elective ophthalmic surgery were allocated randomly into three groups. Anesthesia was induced with thiopentone 4 mg/kg and halothane in combination with 66% N2O and O2 (2 L/min). Patients maintained spontaneous breathing with assisted ventilation to limit the values of end tidal CO2 within the range of 36-44 mmHg, maintained the stable end tidal expiratory 1 MAC halothane concentration for three minutes and followed by 0.1 mg/kg vecuronium in group 1, 0.6 mg/kg rocuronium in group 2, and 0.9 mg/kg rocuronium in group 3. Intubation was attempted as the TOF ratio decreased from 1.0 to 0. The intubation condition was scored by assessing the degree of jaw relaxation, vocal cord opening grades, and cough responses. The overall intubation conditions were graded as excellent, good, fair, and poor on the basis of the scores. Excellent or good intubation conditions were considered satisfactory. After neuromuscular blockade administration, TOF ratio required 160.5 +/- 28.9 seconds in group 1, 70.7 +/- 18.5 seconds in group 2, and 55.7 +/- 13.5 seconds in group 3 to decrease to zero. There is a significant difference between group 1 and group 2 and 3 (p < 0.001, group 1 vs group 2 and group 3). All children were intubated, during which procedures satisfactory intubation conditions were observed in all of the group 3 patients, in 17 of the 20 group 2, and in 16 of the 20 group 1 patients. We concluded that zero of TOF from monitoring the adductor pollicis muscle indicated the proper moment for intubation in anesthetized pediatric patients and it was a reliable guide in adequately anesthetized children to achieve satisfactory intubation conditions following 0.9 mg/kg rocuronium administration.

An alternative technique for accurate placement of central venous catheter tips.

For intravenous electrocardiography (IVECG), a wire stylet is usually utilized as the exploring probe to correctly position the central venous catheter. We present an alternative technique using the transduction probe connected to the original right arm lead of the ECG monitor to accurately position the central venous catheter. We compared the efficacy and quality of the IVECG signals of the two techniques. Sixty patients were randomly enrolled into two groups. In group G, the IVECG signal was conducted from the guide wire to identify the correct catheter tip position. In group T, the IVECG signal was conducted from the transduction probe to ascertain the tip position. The quality of IVECG signals, which included baseline drift, P-wave pattern, and QRS wave pattern, were assessed for 10 seconds. There was no obvious difference between the groups for catheter tip placement time or measured optimal catheter length. During manipulation, the incidence of cardiac dysrhythmia was higher in group G than in group T, but the difference was not significantly different (p = 0.09). Satisfactory IVECG signal quality was observed in 26 of the 30 patients in group G and in 27 of the 30 patients in group T. We conclude that the transduction probe can effectively conduct IVECG signals with no specific additional equipment required. It is an alternative technique for accurate placement of central venous catheter tips during IVECG.