Jong In Han

The analgesic effect of the ultrasound-guided transverse abdominis plane block after laparoscopic cholecystectomy

Background Several methods are performed to control the pain after a laparoscopic cholecystectomy. Recently, the transverse abdominis plane block has been proposed to compensate for the problems developed by preexisting methods. This study was designed to evaluate the effect of the ultrasound-guided transverse abdominis plane block (US-TAP block) and compare efficacy according to the concentration of local analgesics in patients undergoing laparoscopic cholecystectomy. Methods Fifty-four patients undergoing laparoscopic cholecystectomy were randomized into three groups. The patients in Group Control did not receive the US-TAP block. The patients in Group B0.25 and Group B0.5 received the US-TAP block with 0.25% and 0.5% levobupivacaine 30 ml respectively. After the general anesthesia, a bilateral US-TAP block was performed using an in-plane technique with 15 ml levobupivacaine on each side. Intraoperative use of remifentanil and postoperative demand of rescue analgesics in PACU were recorded. The postoperative verbal numerical rating scale (VNRS) was evaluated at 20, 30, and 60 min, and 6, 12, and 24 hr. Postoperative complications, including pneumoperitoneum, bleeding, infection, and sleep disturbance, were also checked. Results The intraoperative use of remifentanil, postoperative VNRS and the postoperative demand of rescue analgesics were lower in the groups receiving the US-TAP block (Group B0.25 and Group B0.5) than Group Control. There were no statistically or clinically significant differences between Group B0.25 and Group B0.5. No complications related to the US-TAP block were observed. Conclusions The US-TAP block with 0.25% or 0.5% levobupivacaine 30 ml (15 ml on each side) significantly reduced postoperative pain in patients undergoing laparoscopic cholecystectomy.

Severe Hypocalcemia Caused by Absorption of Sorbitol-Mannitol Solution during Hysteroscopy

Hysteroscopic procedure can be complicated by intravascular absorption of irrigating fluid. The clinical features of this complication are similar to transurethral resection of the prostate (TURP) syndrome. There have been few reports on hypocalcemia during endoscopoic surgery and clinical implications of hypocalcemia in TURP syndrome have been underestimated. We report a case of TURP syndrome association with a decreased ionized calcium concentration of 0.53 mM/L after the absorption of a large amount of sorbitol-mannitol solution during hysteroscopy. The hypotension which occurred in TURP syndrome did not respond to vasopressor and inotropic agent but responded to the administration of calcium. This case was also accompanied by hyponatremia, hyperglycemia and lactic acidosis through the metabolism of sorbitol.

Antinociceptive synergy between the cannabinoid receptor agonist WIN 55,212-2 and bupivacaine in the rat formalin test.

BACKGROUND:The analgesic interaction between cannabinoids and local anesthetics has not been investigated. We sought to determine the nature of the interaction between the intrathecal cannabinoid receptor agonist (WIN 55,212-2) and bupivacaine using the formalin test. METHODS:Lumbar intrathecal catheters were implanted in male Sprague-Dawley rats. After intrathecal administration of WIN 55,212-2, bupivacaine, or their combination, 50 &mgr;L of 5% formalin was injected subcutaneously into the hindpaw. Dose–response curves were established and the respective ED50 (50% effective dose) values were determined for each agent alone. Fixed-ratio combinations of WIN 55,212-2 and bupivacaine were tested for combined antinociceptive effects in the formalin test and an isobolographic analysis was performed to characterize the pharmacologic interaction of both drugs. RESULTS:Intrathecally administered WIN 55,212-2, bupivacaine, or their combination produced a dose-dependent decrease in the number of flinches during Phase 1 and 2 of the formalin test. Isobolographic analysis revealed a synergistic interaction between intrathecal WIN 55,212-2 and bupivacaine in both phases of the formalin test. In combination, the ED50 value was significantly smaller than the theoretical additive value (P < 0.05). CONCLUSIONS:These results demonstrate that intrathecally coadministered WIN 55,212-2 and bupivacaine provide synergistic antinociceptive interaction in both phases of the formalin test.

Effect of flumazenil on recovery from anesthesia and the bispectral index after sevoflurane/fentanyl general anesthesia in unpremedicated patients

Background Benzodiazepines have a hypnotic/sedative effect through the inhibitory action of γ-aminobutyric acid type A receptor. Flumazenil antagonizes these effects via competitive inhibition, so it has been used to reverse the effect of benzodiazepines. Recently, flumazenil has been reported to expedite recovery from propofol/remifentanil and sevoflurane/remifentanil anesthesia without benzodiazepines. Endogenous benzodiazepine ligands (endozepines) were isolated in several tissues of individuals who had not received benzodiazepines. Methods Forty-five healthy unpremedicated patients were randomly allocated to either flumazenil or a control groups. Each patient received either a single dose of 0.3 mg of flumazenil (n = 24) or placebo (n = 21). After drug administration, various recovery parameters and bispectral index (BIS) values in the flumazenil and control groups were compared. Results Mean time to spontaneous respiration, eye opening on verbal command, hand squeezing on verbal command, extubation and time to date of birth recollection were significantly shorter in the flumazenil group than in the control group (P = 0.004, 0.007, 0.005, 0.042, and 0.016, respectively). The BIS value was significantly higher in flumazenil group than in the control group beginning 6 min after flumazenil administration. Conclusions Administration of a single dose of 0.3 mg of flumazenil to healthy, unpremedicated patients at the end of sevoflurane/fentanyl anesthesia without benzodiazepines resulted in earlier emergence from anesthesia and an increase in the BIS value. This may indicate that flumazenil could have an antagonistic effect on sevoflurane or an analeptic effect through endozepine-dependent mechanisms.

The changes of heart rate variability after unilateral stellate ganglion block.

Background The effect of the unilateral stellate ganglion block (SGB) on cardiovascular regulation remains controversial. We wished to evaluate the changes in heart rate variability (HRV) after a unilateral stellate ganglion block in patients with head and neck pain in the present study. Methods Patients with head and neck pain (n = 89) were studied. HRV was determined before and after a C6 unilateral stellate ganglion block (right-sided SGB, 40; left-sided SGB, 49) using a paratracheal technique with 1% mepivacaine (6 ml). Results There were no significant differences in HRV indices before and after right-sided SGB. The log scale of power in the high frequency range (lnHF) was increased and ratio of power in the low frequency range (LF) to power in the high frequency range (HF) ratio was decreased after left-sided SGB. Conclusions These results demonstrated that left-sided SGB increased parasympathetic activities in patients with head and neck pain.

The frequency of fentanyl-induced cough in children and its effects on tracheal intubation

STUDY OBJECTIVE To determine if fentanyl-induced cough was dose-dependent in children and whether it could affect tracheal intubation. DESIGN Prospective, randomized, double-blinded study. SETTING Operating room of a university-affiliated hospital. PATIENTS 160 ASA physical status I pediatric patients, aged two to 14 years, scheduled for elective surgery during general anesthesia and requiring orotracheal intubation. INTERVENTIONS Patients were divided into two groups. Group 1 patients were given fentanyl at a dosage of one microg/kg; Group 2 patients received two microg/kg of fentanyl. Induction of anesthesia was conducted immediately following cough cessation or one minute after the end of injection with propofol 2.5 mg/kg. At loss of eyelash reflex, rocuronium 0.6 mg/kg was given intravenously (IV). Two minutes later, tracheal intubation was started. MEASUREMENTS Onset and degree of cough and intubating conditions were observed and recorded. MAIN RESULTS No statistically significant differences in frequency of coughing or in intubating conditions between the two groups were noted. Cough severity in Group 1 was statistically lower than that of Group 2 (P < 0.05). Onset of cough in Group 2 (12.2 +/- 3.4 sec) was statistically shorter than in Group 1 (16.9 +/- 7.6 sec, P < 0.05). CONCLUSION Fentanyl at doses of one and two microg/kg may induce coughing in pediatric patients.

Gabapentin inhibits the activity of the rat excitatory glutamate transporter 3 expressed in Xenopus oocytes

Gabapentin, a derivative of γ-aminobutyric acid (GABA), is used to treat epilepsy and neuropathic pain. The pharmacological mechanisms for gabapentin effects are not completely elucidated. We investigated the effect of gabapentin on the activity of excitatory amino acid transporter 3 (EAAT3) that can regulate extracellular glutamate concentrations. EAAT3 was expressed in Xenopus oocytes. Membrane currents were recorded after application of l-glutamate in the presence or absence of different concentrations of gabapentin (1-300μM) by using a two-electrode voltage clamp. To determine the effect of gabapentin on Vmax and Km of EAAT3 for l-glutamate, l-glutamate at 3-300μM was used. To study the effects of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3K) on gabapentin-induced changes in EAAT3 activity, oocytes were incubated with the PKC activator (Phorbol 12-myristate 13-acetate, PMA), the PKC inhibitors (chelerythrine or staurosporine), and the PI3K inhibitor wortmannin. Gabapentin decreased EAAT3 activity in a concentration-dependent manner and EAAT3 activity was significantly inhibited by 10-300μM gabapentin. Gabapentin significantly decreased Vmax without affecting Km. PMA increased EAAT3 activity; however, gabapentin attenuated the PMA-induced increase in EAAT3 activity. Pre-incubation of oocytes with chelerythrine, staurosporine, or wortmannin decreased basal EAAT3 activity, which was further reduced by gabapentin. We conclude that gabapentin decreases EAAT3 activity at clinically relevant and higher concentrations, in which PKC and PI3K may not be involved. The results suggest that EAAT3 might not be a target for the anticonvulsant action of gabapentin.

The preemptive analgesic effect of ketorolac and propacetamol for adenotonsillectomy in pediatric patients

BACKGROUND Both ketorolac and propacetamol are used postoperatively to control mild to moderate pain. This study compared the analgesic efficacy of ketorolac and propacetamol delivered either preoperatively or postoperatively, and assessed the preemptive analgesic effect of ketorolac and propacetamol for adenotonsillectomy. METHODS One hundred and two pediatric patients were divided randomly into four groups. The K1 and P1 groups received ketorolac 1 mg/kg or propacetamol 30 mg/kg after induction, respectively, whereas the K2 and P2 groups received each drug at the end of the operation, respectively. After adenotonsillectomy, we measured the NRS (Numerical Rating Scale), FPS (Faces Pain Scale) and OPS (Objective Pain scale) at 15, 30 and 60 min after arriving at the postanesthesia care unit. RESULTS There were no significant differences in the NRS, FPS and OPS between K1 and K2 and between P1 and P2 for 60 min after operation at the postanesthesia care unit. CONCLUSIONS These results suggest that both ketorolac (1 mg/kg) and propacetamol (30 mg/kg) have no preemptive analgesic effects during 1 hour after adenotonsillectomy.

Effects of clonidine on the activity of the rat glutamate transporter EAAT3 expressed in Xenopus oocytes

Background Clonidine has been shown to be a potent neuroprotectant by acting at α2 receptors on glutamatergic neurons to inhibit the release of glutamate. The aim of this study is to investigate the effects of clonidine on the activity of EAAT3 that can regulate extracellular glutamate. Methods EAAT3 was expressed in the Xenopus oocytes. Using a two-electrode voltage clamp, membrane currents were recorded after application of 30 µM L-glutamate both in the presence and absence of various concentrations of clonidine. To determine the effects of clonidine on the Km and Vmax of EAAT3 and the reversibility of clonidine effects, membrane currents were recorded after the application of various concentrations of L-glutamate both in the presence and absence of 1.50 × 10-7 M clonidine. Results Clonidine reduced the EAAT3 responses to L-glutamate in a concentration-dependent manner. This inhibition was statistically significant at higher concentrations than at the clinically relevant range. Clonidine at 1.50 × 10-7 M reduced the Vmax, but did not affect the Km of EAAT3 for L-glutamate. Conclusions These results suggest that the direct inhibition of EAAT3 activity is not related to the sedation effect of clonidine and that the clonidine-induced reduction of EAAT3 activity provides additional data for the possible involvement of glutamatergic hyperactivity in the proconvulsant effect of clonidine.

Airway management in patients with deep neck infections: A retrospective analysis.

AbstractSecuring the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method.We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologists perspective.When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected.When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients’ symptoms is needed.