Woo Jong Shin

Thermosoftening treatment of the nasotracheal tube before intubation can reduce epistaxis and nasal damage.

We evaluated whether a thermosoftening treatment with warm saline of a nasotracheal preformed tube can improve navigability through the nasal passageways and reduce epistaxis and nasal damage. A total of 150 patients were randomly allocated to three groups: Group I (untreated tube group, n = 50), Group II (35°C treated tube group, n = 50), and Group III (45°C treated tube group, n = 50). In Groups II and III, the tubes were softened at 35 ± 2°C and 45 ± 2°C with warm saline, respectively. In Group I the tube was prepared at room temperature (25 ± 2°C). The incidence of epistaxis and nasal damage in Groups II and III was significantly less than that of Group I (P < 0.05). Despite the more frequent incidence of smooth passage in Group III, no statistical difference was found among the groups. Logistic regression analysis also confirmed that epistaxis was more likely to be reduced when the tube had been thermosoftened (odds ratio = 1.46, 95% confidence interval = 1.02, 2.11). We conclude that simple thermosoftening treatment of the nasotracheal tube with warm saline helps to reduce epistaxis and nasal damage. Implications Thermosoftening treatment of a nasotracheal tube with warm saline before intubation can effectively reduce epistaxis and nasal damage. This technique is safe, easy, and suitable for all types of tubes and does not require additional implements.

Ultrasound-guided greater occipital nerve block for patients with occipital headache and short term follow up

Background The greater occipital nerve (GON) block has been frequently used for different types of headache, but performed with rough estimates of anatomic landmarks. Our study presents the values of the anatomic parameters and estimates the effectiveness of the ultrasound-guided GON blockade. Methods The GON was detected using ultrasound technique and distance from external occipital protuberance (EOP) to GON, from GON to occipital artery and depth from skin to GON was measured in volunteers. Patients with occipital headache were divided into two groups (ultrasound-guided block: group S, conventional blind block: group B) and GON block was performed. The same parameters were measured on group S and VAS scores were assessed at pretreatment, 1 week and 4 weeks after treatment on both groups. Results The GON had distance of 23.1 ± 3.4 mm (right) and 20.5 ± 2.8 mm (left) from EOP to GON. Its depth below the skin was 6.8 ± 1.5 mm (right) and 7.0 ± 1.3 mm (left). The distance from GON to occipital artery was 1.5 ± 0.6 mm (right) and 1.2 ± 0.6 mm (left) in volunteers. Initial VAS score of group S and group B patients were 6.4 ± 0.2 and 6.5 ± 0.2. VAS score of 4 weeks after injection were 2.3 ± 0.2 on group S and 3.8 ± 0.3 on group B (P = 0.0003). Conclusions The parameters measured in this study should be useful for GON block and ultrasound-guided blockade is likely to be a more effective technique than blind blockade in occipital headache treatment.

Modulation of noninactivating K+ channels in rat cerebellar granule neurons by halothane, isoflurane, and sevoflurane

Neuronal baseline K+ channels were activated by several volatile anesthetics. Whole-cell recordings from cultured cerebellar granule neurons of 7-day-old male Sprague-Dawley rats showed outward-rectifying K+ currents with a conductance of ∼1.1 ± 0.3 nS (n = 20) at positive potentials. The channel activity was noninactivating, exhibited no voltage gating, and was insensitive to conventional K+ channel blockers. Clinically relevant concentrations of halothane (112, 224, 336, and 448 &mgr;M) dissolved in Ringer’s solution increased outward currents by 29%, 50%, 63%, and 94%, respectively (n = 5;P < 0.05; analysis of variance [ANOVA]). Similar increases in currents were produced by isoflurane (274, 411, 548, and 822 &mgr;M), which increased outward currents by 22%, 47%, 52%, and 60%, respectively (n = 5;P < 0.05; ANOVA). Sevoflurane 518 &mgr;M increased outward currents by 225% (n = 10;P < 0.05; ANOVA). In all experiments, channel activity quickly returned to baseline levels during wash. The outward-rectifying whole-cell current-voltage curves were consistent with the properties of anesthetic-sensitive KCNK channels. These results support the idea that noninactivating baseline K+ channels are important target sites of volatile general anesthetics.

Neuromuscular interactions between mivacurium and esmolol in rabbits

We compared the dose–response relationship and the neuromuscular blocking effects of mivacurium during infusions of esmolol in 40 anaesthetised rabbits. Train‐of‐four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured. Plasma cholinesterase activity decreased by 13% after esmolol infusion. The ED95 of mivacurium increased significantly from 29 (4.8) μgkg−1 with placebo to 61 (9.8) μgkg−1 during esmolol 100 μgkg−1.min−1, 49 (8.2) μgkg−1 during esmolol 300 μgkg−1.min−1 and 54 (7.3) μgkg−1 during esmolol 500 μgkg−1.min−1, respectively (p < 0.001). The duration of neuromuscular block with mivacurium 0.16 mgkg−1 was prolonged by 30% with esmolol due to diminished plasma cholinesterase activity (p < 0.05). Heart rate and mean arterial blood pressure decreased by 15% with esmolol (p < 0.05). The results of this study show that, in rabbits, esmolol decreased plasma cholinesterase activity, antagonised the neuromuscular blocking potency of mivacurium and prolonged its neuromuscular blocking effect.

A cardiovascular collapse occurred in the beach chair position for shoulder arthroscopy under general anesthesia -A case report-

The occurrence of severe hypotension and bradycardia, following placing to the beach chair position from supine during general anesthesia for repair of tendon injury of the rotator cuff of shoulder in a healthy 50 year-old man was described. The Bezold-Jarisch reflex, which is known to inhibit cardiovascular reflex and composed of three kinds of symptoms such as vasodilation, bradycardia and hypotension, has been reported mainly in peripheral nerve block, and may occur during orthostasis, hypovolemia, hemorrhage, supine inferior vena cava compression in pregnancy, interscalene block for shoulder surgery in the sitting position and so on. The bradycardia and hypotension can be more aggravated when causative elements overlaps each other. Anticholinergics and vasopressor were injected intravenously, and position of the patient was changed to the supine position immediately resulting in a normal vital signs dramatically.

The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction without muscle relaxation

STUDY OBJECTIVE To determine the most suitable effect-site concentration of remifentanil during lightwand intubation when administered with a target-controlled infusion (TCI) of propofol at 4.0 μg/mL without neuromuscular blockade. DESIGN Prospective study using a modified Dixons up-and-down method. SETTING Operating room of an academic hospital. PATIENTS 28 ASA physical status 1 and 2 patients, aged 18-65 years, scheduled for minor elective surgery. INTERVENTIONS Anesthesia was induced by TCI propofol effect-site concentration to 4.0 μg/mL, and the dose of remifentanil given to each patient was determined by the response of the previously tested patient using 0.2 ng/mL as a step size. The first patient was tested at a target effect-site concentration of 4.0 ng/mL of remifentanil. If intubation was successful, the remifentanil dose was decreased by 0.2 ng/mL; if it failed, the remifentanil dose was increased by 0.2 ng/mL. Successful intubation was defined as excellent or good intubating conditions. MEASUREMENTS AND MAIN RESULTS The remifentanil effect-site concentration was measured. The optimal effect-site concentration of remifentanil for lightwand tracheal intubation during propofol induction using 2% propofol target effect-site concentration to 4 μg/mL was 2.16 ± 0.19 ng/mL. From probit analysis, the effect-site concentration of remifentanil required for successful lightwand intubation in 50% (EC50) and 95% (EC95) of adults was 2.11 ng/mL (95% CI 1.16-2.37 ng/mL) and 2.44 ng/mL (95% CI 2.20-3.79 ng/mL), respectively. CONCLUSION A remifentanil effect-site concentration of 2.16 ± 0.19 ng/mL given before a propofol effect-site concentration of 4 μg/mL allowed lightwand intubation without muscle relaxant.

The sedative effects of the intranasal administration of dexmedetomidine in children undergoing surgeries compared to other sedation methods: A systematic review and meta-analysis

STUDY OBJECTIVE Administration of intranasal dexmedetomidine for sedation is comfortable and effective in children who are afraid of needles, and it offers efficient sedation similar to that of intravenous administration. We performed a systematic review and meta-analysis to evaluate the clinical effects of the pre-procedural administration of intranasal dexmedetomidine. DESIGN We identified randomized controlled trials (RCTs) that compared intranasal dexmedetomidine administration to other administration methods of various sedatives or placebo from MEDLINE, EMBASE, Cochrane, KoreaMed and hand searches of trial registries. SETTING Pediatrics who underwent interventional procedures and surgeries. PATIENTS Children under the age of 18. INTERVENTIONS Studies were included if they were compatible with the criteria that dexmedetomidine was administered intranasally. MEASUREMENTS We pooled data on the sedation status as the primary outcome and considered the behavioral score, blood pressure, heart rate and side effects to be secondary outcomes. Risk ratio (RR) and the standardized mean difference (SMD) with 95% confidence intervals (CIs) were calculated for dichotomous and continuous outcomes, respectively. MAIN RESULTS This meta-analysis included 11 RCTs. The SMD for the sedative effects of intranasal dexmedetomidine was -2.45 (random, 95% CI; -3.33, -1.58) for continuous outcomes and RR of unsatisfactory patient outcome was 0.42 (M-H, random 95% CI; 0.26, 0.68 I2=45%) for dichotomous outcomes compared to that of intranasal saline. The SMD for the sedative effects of intranasal dexmedetomidine was -0.41 (random, 95% CI; -1.09, 0.27 I2=69%) for continuous outcomes and RR was 0.43 (M-H, random 95% CI; 0.32, 0.58 I2=0%) for dichotomous outcomes compared to that of per os benzodiazepines. CONCLUSIONS This review suggests that intranasal dexmedetomidine is associated with better sedative effects than oral benzodiazepines without producing respiratory depression, but it had a significantly delayed onset of effects.

The general anesthesia experience of deletion 8p syndrome patient -A case report-.

A deletion 8p syndrome is a relatively uncommon congenital disease characterized by mental retardation associated with multiple malformation that make anesthetic management a challenge. Anesthetic management of a patient with deletion 8p syndrome may pose a serious problem mainly from difficult tracheal intubation, aspiration complication and cardiac malformation. We experienced a case of 10 year-old boy with a deletion 8p syndrome who underwent appendectomy under the general anesthesia. Intubation was performed by video glidescope after unsuccessful attempt with Macintosh laryngoscope. A high arched palate, short neck, poor patient cooperation due to mental retardation and occasional autistic behaviour made airway management difficult. This case should alert anesthesiologists to the greater difficulties of managing patients with deletion 8p syndrome.

Bilateral upper lobe pulmonary edema during gynecologic laparoscopic surgery in the Trendelenberg position -A case report-.

A 25-year-old woman was diagnosed with a ruptured ectopic pregnancy. During laparoscopic surgery, the patient was in the Trendelenberg position (20° degrees). Massive froth in the endotracheal tube was observed at the end of surgery. A portable chest x-ray, checked at the end of the operation, showed diffuse haziness in both upper lung fields. After one hour of aggressive treatment with drugs and positive mechanical ventilation, the amount of froth in the endotracheal tube was reduced considerably. Considering the symptom and radiologic findings, we concluded that diffuse bilateral upper lung field haziness was due to atypical pulmonary edema. We speculated that the rapid improvement of pulmonary edema was due to redistribution of fluid to the lowest part of lung by immediate reversing the patients Trendelenberg position, along with aggressive treatment.

Comparison of volume-control and pressure-control ventilation during one-lung ventilation

BACKGROUND We hypothesized that pressure control ventilation allows a more even distribution in the lung and better maintenance of the mean airway pressure than is achieved with volume control ventilation. We try to compare the effect of pressure control ventilation (PC) with that of volume control ventilation without an end-inspiratory pause (VC) during one-lung ventilation (OLV) in an anesthetized, paralyzed patient for performing thoracopic bullectomy of the lung. METHODS We ventilated 20 patients with VC and PC after the insertion of a thoracoscope in continual order for, at least for 15 minutes, for each, VC and PC procedure. At the end of VC and PC, the respiratory mechanics, gasometrics, and hemodynamic parameters were measured and collected. RESULTS We found no significant differences between VC and PC except for the peak inspiratory airway pressure (PIP), the mean airway pressure and the arterial oxygen partial pressure (PaO2). The PIP was significantly decreased from 27.0 +/- 6.0 cmH2O (VC) to 21.8 +/- 5.4 cmH2O (PC). The mean airway pressure was significantly increased from 8.6 +/- 1.6 cmH2O (VC) to 9.4 +/- 2.0 cmH2O (PC), and the PaO2 was significantly increased from 252.9 +/- 97.3 mmHg (VC) to 285.2 +/- 103.8 mmHg (PC). CONCLUSIONS If PC allows mechanical ventilation with the same tidal volume and respiratory rate as VC during OLV, then PC significantly increases the PaO2 but this is not clinically significant, and the PC significantly decreases the PIP, which induces barotrauma or volutrauma when the PIP is excessively high.