Comparison of Postoperative Nausea and Vomiting Incidence between Remimazolam and Sevoflurane in Tympanoplasty with Mastoidectomy: A Single-Center, Double-Blind, Randomized Controlled Trial.

Background and Objectives: Postoperative nausea and vomiting (PONV) is a common adverse effect of general anesthesia, especially in middle ear surgery. Remimazolam is a newer benzodiazepine recently approved for use in general anesthesia. This study aimed to compare the incidence rate of PONV after tympanoplasty with mastoidectomy between using remimazolam and sevoflurane. Materials and Methods: This study included 80 patients undergoing elective tympanoplasty with mastoidectomy. The patients were randomly assigned to either the remimazolam or sevoflurane group. The primary outcome was the incidence rate of PONV 12 h after surgery. The secondary outcomes were the incidence rate of PONV 12-24 and 24-48 h after surgery, severity of PONV, incidence rate of vomiting, administration of rescue antiemetics, hemodynamic stability, and recovery profiles. Results: The incidence rate of PONV 0-12 h after tympanoplasty with mastoidectomy was significantly lower in the remimazolam group compared with that in the sevoflurane group (28.9 vs. 57.9%; p = 0.011). However, the incidence rate of delayed PONV did not differ between the two groups. PONV severity in the early periods after the surgery was significantly lower in the remimazolam group than in the sevoflurane group. The incidence rate of adverse hemodynamic events was lower in the remimazolam group than in the sevoflurane group, but there was no difference in the overall trends of hemodynamic data between the two groups. There was no difference in recovery profiles between the two groups. Conclusions: Remimazolam can significantly reduce the incidence rate of early PONV after tympanoplasty with mastoidectomy under general anesthesia.

Comparison of remimazolam-remifentanil and propofol-remifentanil during laparoscopic cholecystectomy.

BACKGROUND: Remimazolam is a novel benzodiazepine with fast onset and short half-life. We compared the effects of remimazolam and propofol on recovery profiles for general anesthesia in patients undergoing laparoscopic cholecystectomy. METHODS: We randomly assigned 108 patients to either a remimazolam (n=54) or propofol (n=54) group. Remimazolam and propofol were used for induction and maintanance of anesthesia. Following anesthesia, we recorded the time until an Aldrete score of 9 was achieved as the primary surrogate marker of complete recovery. The time to reach a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 2 and the time from the end of anesthesia to eye opening time, recovery time of orientation, time to spontaneous breathing, extubation time, and the time required for analgesics were measured. Heart rate, blood pressure, and bispectral index were assessed before, during, and after pneumoperitoneum. RESULTS: We included 101 patients in the analysis. In the remimazolam group, it took longer to reach an Aldrete score of 9 after the drug infusion ended (P = 0.031). There was no difference in the time to reach MOAA/S 2 between the two groups. The time to eye opening, recovery time of orientation, and time required for analgesics were longer and heart rate was higher in the remimazolam group. Neither blood pressure, nor extubation time differed between groups. CONCLUSIONS: Remimazolam and propofol provided safe induction and maintenance of anesthesia in patients undergoing laparoscopic cholecystectomy. The recovery time from anesthesia was longer than that with propofol. Fewer hemodynamic changes were observed with remimazolam, but further studies are needed.

Comparing the Pericapsular Nerve Group Block and the Lumbar Plexus Block for Hip Fracture Surgery: A Single-Center Randomized Double-Blinded Study.

Lumbar plexus blocks (LPBs) are routinely employed for analgesia in hip fracture surgery; however, a novel regional technique, the pericapsular nerve group (PENG) block, potentially offers comparable pain reduction while preserving motor function. Patients aged 45-90 years who underwent hip fracture surgery were allocated to receive either a PENG block or an LPB for analgesia. The primary outcome was the incidence of quadriceps motor block (defined as the paresis or paralysis of the knee extension) at 12 h postoperatively. The secondary outcomes included the performance time, the time to first analgesic requirement, postoperative intravenous (IV) fentanyl consumption, the ability to undergo physiotherapy at 24 and 48 h, complications, sensory and motor block assessments, postoperative numeric rating scale (NRS) pain scores, and patient outcome questionnaires. There was a significantly lower incidence of quadriceps motor block at 6 h (26.7% vs. 80.0%; p < 0.001) and at 12 h (20.0% vs. 56.7%; p = 0.010). The PENG block provided better preservation of the sensory block as well as better performance time (p < 0.001) and time to first analgesia requirement (p = 0.034), whereas the LPB resulted in lower postoperative IV fentanyl consumption at 24 h (p = 0.013). The PENG block demonstrated superiority over the LPB in preserving quadriceps strength and patient satisfaction without any substantial complications, despite higher opioid consumption within the first 24 h post-surgery.

Reduced Opioid Consumption with Pericapsular Nerve Group Block for Hip Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial.

The pericapsular nerve group (PENG) block targets the nerves innervating the anterior hip surface; however, few studies on this technique are currently available. We investigated the effects of the PENG block on postoperative opioid consumption after a hip surgery. This was a randomized, double-blind, placebo-controlled study conducted at a single institution. Fifty patients undergoing hip surgery were randomly allocated, 25 in each group, to receive a PENG block either using 25 mL of 0.5% ropivacaine (PENG group) or 25 mL of saline (control group). The primary outcome was the total opioid consumption 24 h postoperatively. The secondary outcomes were postoperative pain scores, time to first opioid demand, sensory block efficiency, quadriceps muscle strength, complications, and patient satisfaction. Compared with those in the control group, patients in the PENG group had a significantly lower total opioid consumption 24 h postoperatively (440.72 ± 242.20 µg vs. 611.07 ± 313.89 µg, P = 0.037) and significantly lower pain scores at 30 min postblock and 6 postoperatively (P < 0.001 and P < 0.001, respectively). The time to first opioid demand was significantly shorter in the control group than in the PENG group (P < 0.001). Sensory block effectiveness was better in the PENG group 30 min postblock and 6 and 12 h postoperatively than in the control group. Patient satisfaction was also better in the PENG group than in the control group. There were no differences in the other outcomes. The PENG block reduced the total opioid consumption in the first 24 h after hip surgery with no significant effects on quadriceps muscle strength and complication rate. This study was registered at the Korea Clinical Research Information Service (cris.nih.go.kr; Reg. No. KCT0006348) on July 16, 2021.

Comparison of prophylactic effect of topical Alchemilla vulgaris in glycerine versus that of dexamethasone on postoperative sore throat after tracheal intubation using a double-lumen endobronchial tube: a randomized controlled study.

BACKGROUND: Sore throat and hoarseness frequently occur following general anesthesia with tracheal intubation and are effectively reduced when dexamethasone is used prophylactically. Alchemilla vulgaris in glycerine (Neo Mucosal Activator®) suppresses inflammatory response, possibly relieving sore throat. METHODS: We enrolled 94 patients (age ≥ 18 years) scheduled for thoracic surgery using double-lumen tube intubation. Before intubation, 0.2 mg/kg of dexamethasone was administered intravenously and 2 ml of normal saline was sprayed into the oropharyngeal cavity (Group D; n = 45), or 0.04 ml/kg normal saline was administered intravenously and 1 g of Neo Mucosal Activator® mixed with 1 ml of normal saline was sprayed into the oropharyngeal cavity (Group N; n = 43), in a double blind and prospectively randomized manner. Postoperative sore throat and hoarseness were recorded using a numeral rating scale and a 4-point scale to detect a change in voice quality following tracheal extubation (at 1, 6, and 24 h). The primary outcome was the incidence of sore throat at 24 h following surgery. The secondary outcomes were incidence and severity of sore throat and hoarseness. RESULTS: There were no significant differences in the incidence of sore throat at 24 h following surgery (57.8% vs. 46.5%; P = 0.290) or in the incidence and intensity of sore throat and hoarseness at 1, 6, and 24 h following surgery between the groups. CONCLUSIONS: A. vulgaris in glycerine did not significantly differ from dexamethasone for preventing sore throat and hoarseness owing to intubation.

Comparison between two different concentrations of a fixed dose of ropivacaine in interscalene brachial plexus block for pain management after arthroscopic shoulder surgery: a randomized clinical trial.

BACKGROUND: Only a few studies have evaluated the differences between varying concentrations of a fixed dose of local anesthetics. This study was conducted to compare the effects of two different concentrations of a fixed dose of ropivacaine used in ultrasound-guided interscalene brachial plexus block. METHODS: This prospective, randomized, double-blind study included 62 patients who underwent arthroscopic surgery under general anesthesia. The patients were randomly assigned to receive ultrasound-guided interscalene block with 75 mg of ropivacaine at one of two concentrations: 0.75% (10 ml; group C) or 0.375% (20 ml; group V). Time to onset of sensory blockade, degree of blockade, pulmonary function changes, analgesic duration of the interscalene block, postoperative opioid requirement within 24 h, postoperative pain scores, satisfaction, and incidence of complications were recorded. RESULTS: Although the time to onset of sensory blockade was shorter for group C (P = 0.015), successful blockade was achieved at 30 min after the interscalene block in both groups. The analgesic duration of the interscalene block was not significantly different between the groups. The amount of opioid used within 24 h after surgery was significantly reduced for group V compared with group C (P = 0.016). The rest of the parameters did not show any significant differences between the two groups. CONCLUSION: Compared with 10 ml of 0.75% ropivacaine, interscalene block with 20 ml of 0.375% ropivacaine could be effective for the reduction of postoperative opioid requirement within 24 h after surgery despite it might not prolong the analgesic duration.

Comparison of clinical performance of i-gelⓇ and Baska MaskⓇ during laparoscopic cholecystectomy.

BACKGROUND: The supraglottic airway device is an appropriate alternative to tracheal intubation in laparoscopic surgery. We compared the Baska MaskⓇ with i-gelⓇ by measuring the oropharyngeal leak pressure (OLP) and hemodynamic and respiratory parameters during laparoscopic cholecystectomy. METHODS: A total of 97 patients were randomly allocated to either i-gel group (n = 49) or Baska Mask group (n = 48). Insertion time, number of insertion attempts, fiber-optic view of the glottis, and OLP were recorded. Heart rate, mean arterial pressure, peak airway pressure (PAP), lung compliance, and perioperative complications were assessed before, during, and after pneumoperitoneum. RESULTS: There were no significant differences between the two groups regarding demographic data, insertion time, fiber-optic view of the glottis, and the use of airway manipulation. The OLP was higher in the Baska Mask group than in the i-gel group (29.6 ± 6.8 cmH2O and 26.7 ± 4.5 cmH2O, respectively; P = 0.014). Heart rate, mean arterial pressure, PAP, and lung compliance were not significantly different between the groups. The incidence of perioperative complications was small and not statistically significant. CONCLUSIONS: Both the i-gel and Baska Mask provided a satisfactory airway during laparoscopic cholecystectomy. Compared with the i-gel, the Baska Mask demonstrated a higher OLP.

A comparison of i-gel™ and Laryngeal Mask Airway Supreme™ during general anesthesia in infants.

BACKGROUND: The i-gel™ (i-gel) and Laryngeal Mask Airway Supreme™ (LMA Supreme) have been safely used in children. We compared the airway performance of the i-gel and LMA Supreme in infants undergoing general anesthesia. METHODS: Sixty infants with American Society of Anesthesiologists physical status I or II were randomly assigned to place either the i-gel or the LMA Supreme. The size 1 or 1.5 of each airway was selected by the weight of infants. The primary outcome variable was oropharyngeal leak pressure (OLP). We also assessed insertion success rate, insertion time, fiberoptic view of the larynx, airway quality, airway manipulations, and perioperative complications. RESULTS: Demographic data did not differ between the two groups. Insertion success rate was similar in both groups. OLP for the i-gel (26.0 ± 3.8 cmH2O) was higher than for the LMA Supreme (23.7 ± 3.2 cmH2O) (P = 0.016). Insertion time for the i-gel (16.4 ± 2.8 s) was shorter than for the LMA Supreme (18.5 ± 2.7 s) (P = 0.002). There were no differences in fiberoptic view of the larynx, airway quality, airway manipulations, and complications between the two groups. CONCLUSIONS: This study demonstrated that the i-gel and LMA Supreme provided a similar performance of airway in infants. Compared with the LMA Supreme, the i-gel provided shorter insertion time and higher OLP in infants.

Effective doses of cisatracurium in the adult and the elderly.

BACKGROUND: There are few information about the differences of the effective dose (ED) of cisatracurium between the adult and the elderly. We investigated the ED and the onset time of cisatracurium in the adults and the elderly. METHODS: We studied two hundred patients of the adults aged 20 through 64 years and the elderly aged ≥ 65 years, with American Society of Anesthesiologists physical status I or II. Each 100 patients with 20 patients of each dose group, randomly selected from 30, 40, 50, 60 or 70 µg/kg of cisatracurium, were randomly allocated to the adults and the elderly groups. We recorded the 0.1 Hz single twitch responses of the adductor pollicis and the onset times to maximal blockade. The magnitude of muscle relaxation was recorded by using an acceleromyography. The effect of cisatracurium on single twitch was calculated as percent reduction. After converting each drug dose into logarithm and percent reduction of the muscle reduction into probit, the EDs representing the muscle relaxation effects of 5%, 25%, 50%, 75% and 95% were estimated using the linear regression analysis. RESULTS: No significant differences were found in age, weight, height, or body mass index within or between the groups. The ED50 and ED95 of the adult group were 35.39 and 59.58 µg/kg. The ED50 and ED95 of the elderly group were 34.89 and 55.50 µg/kg, respectively. The onset times were 375.4 ± 76.9 seconds in the adult group and 369.1 ± 70.0 seconds in the elderly group. CONCLUSIONS: The ED and the onset time were not significantly different between the adult and the elderly.

The prophylactic effect of dexamethasone on postoperative sore throat in prone position surgery.

BACKGROUND: Sore throat and hoarseness are common complications after general anesthesia with tracheal intubation. The position for patients can affect the incidence of postoperative sore throat (POST) by causing displacement of the endotracheal tube. This study investigated the prophylactic effect of dexamethasone in prone position surgeries. METHODS: One hundred-fifty patients undergoing lumbar spine surgery (18-75 yr) were randomly allocated into the normal saline group (group P, n = 50), dexamethasone 0.1 mg/kg group (group D1, n = 50) or dexamethasone 0.2 mg/kg group (group D2, n = 50). The incidence and severity of POST, hoarseness, and cough were measured using direct interview at 1, 6, and 24 h after tracheal extubation. The severity of POST, hoarseness, and cough were graded using a 4-point scale. RESULTS: At 1, 6, and 24 h after extubation, the incidence of sore throat was significantly lower in group D1 (1 h; P = 0.015, 6 h; P < 0.001, 24 h; P = 0.038) and group D2 (1 h; P < 0.001, 6 h; P < 0.001, 24 h; P = 0.017) compared to group P. There were less number of patients in the groups D1 and D2 than group P suffering from moderate grade of POST at 1, 24 h after extubation. The incidence of hoarseness at 1, 6, and 24 h after extubation was significantly lower in groups D2 than group P (P < 0.001). There were no significant differences in the incidence of cough among the three groups. CONCLUSIONS: The prophylactic use of dexamethasone 0.1 mg/kg and 0.2 mg/kg in prone surgery reduces the incidence of postoperative sore throat and dexamethasone 0.2 mg/kg decreases the incidence of hoarseness.

Comparison of i-gel® and LMA Supreme® during laparoscopic cholecystectomy.

BACKGROUND: In laparoscopic surgical procedures, many clinicians recommend supraglottic airway devices as good alternatives to intubation. We compared the i-gel® (i-gel) and LMA Supreme® (Supreme Laryngeal Mask Airway, SLMA) airway devices during laparoscopic cholecystectomy regarding sealing pressure and respiratory parameters before, during, and after pneumoperitoneum. METHODS: Following Institutional Review Board approval and written informed consent, 93 patients were randomly allocated into the i-gel (n = 47) or SLMA group (n = 46). Insertion time, number of insertion attempts, and fiberoptic view of glottis were recorded. Oropharyngeal leak pressure (OLP), the use of airway manipulation, peak inspiratory pressure, lung compliance, and hemodynamic parameters were measured before, during, and after pneumoperitoneum. RESULTS: There were no significant differences between the two groups regarding demographic data, insertion time, fiberoptic view of glottis, and the use of airway manipulation. The gastric tube insertion time was longer in the i-gel group (20.4 ± 3.9 s) than in the SLMA group (16.7 ± 1.6 s) (P < 0.001). All devices were inserted on the first attempt, excluding one case in each group. Peak inspiratory pressure, lung compliance, and OLP changed following carbon dioxide pneumoperitoneum in each group, but there were no significant differences between the groups. CONCLUSIONS: Both the i-gel and SLMA airway devices can be comparably used in patients who undergo laparoscopic cholecystectomy, and they offer similar performance including OLP.

A comparison of i-gel™ and LMA Supreme™ in anesthetized and paralyzed children.

BACKGROUND: Both the i-gel™ (i-gel) and LMA Supreme™ (Supreme) are new single-use second generation supraglottic airway devices available in pediatric sizes. This study was designed to investigate the i-gel in comparison with the Supreme in children undergoing general anesthesia. METHODS: One hundred children with American Society of Anesthesiologists physical status I or II undergoing general anesthesia were randomly assigned to either the i-gel or the Supreme group (50 children in each group). The device size was chosen according to weight of the children. We assessed the insertion success rate, insertion time, oropharyngeal leak pressure, grade of the fiberoptic glottic view, number of airway manipulations required, and postoperative complications. RESULTS: There were no differences in the demographic data between the two groups. The success rate of insertion was same in both groups. The insertion time of the i-gel was longer than that of Supreme (P = 0.004). The oropharyngeal leak pressure in the i-gel group was higher than that in the Supreme group (P = 0.013). On fiberoptic examination, the vocal cords were visible in 90% of the children in the i-gel group and in 96% of the children in the Supreme group. The number of airway manipulations required was higher in the i-gel group (14 cases) than in the Supreme group (1 case) (P < 0.001). There were no differences in complications including blood staining of the device and sore throat between both groups. CONCLUSIONS: Both the i-gel and Supreme provided a satisfactory airway during general anesthesia in children. Compared to the Supreme, the i-gel demonstrated a higher oropharyngeal leak pressure, longer time for insertion, and a greater number of airway manipulations during anesthesia.

Anesthetic management of transoral natural orifice transluminal endoscopic surgery: two cases report.

Natural orifice transluminal endoscopic surgery (NOTES) is an evolving field of minimally invasive surgery. NOTES reaches the target organ by inserting the endoscope through a natural orifice (e.g. mouth, anus, urethra, vagina) and offers advantages of less postoperative pain and lower complication rate. Since its first description in 2004, NOTES has progressed from use on animal models to humans. We experienced anesthetic care of two patients who underwent transoral NOTES under general anesthesia.

The synergistic effect of gentamicin and clindamycin on rocuronium-induced neuromuscular blockade.

BACKGROUND: Gentamicin reduces acetylcholine release and clindamycin causes end-plate ion channel blockade. Because of these reasons, two drugs show muscular relaxant effect and potentiate the action of nondepolarizing neuromuscular agents. This study was intended to evaluate the effect of gentamicin and clindamycin on rocuronium-induced neuromuscular blockade and the interaction between these drugs. METHODS: Male Sprague-Dawley rats' phrenic nerves and diaphragms were installed in a bath containing Krebs solution. They were divided into three study groups. The first group was pre-treated with 0.1 (n = 3), 0.2 (n = 4) or 0.5 (n = 3) mM gentamicin and the tension was measured as the concentration of rocuronium was increased. The second group was experimented by increasing gentamicin on 0.25 (n = 5), 0.5 (n = 6) or 1.0 (n = 6) mM clindamycin. The final group was pre-treated with various combinations of gentamicin and clindamycin. The drug concentration was gradually increased until single twitch tension decreased by around 80%. Effective concentration was calculated using a probit model and interaction indices derived the Loewe additivity. RESULTS: The administration of gentamicin and the combination of gentamicin and clindamycin enhanced rocuronium-induced neuromuscular blockade. At 0.2 and 0.5 mM gentamicin, synergistic interactions with rocuronium were observed. Likewise, at 0.5 and 1.0 mM clindamycin, synergistic interactions with gentamicin appeared. When all three drugs were combined, in the tetanic fade, all the groups except for those administered with 0.01 mM gentamicin and 0.25 mM clindamycin showed synergistic interactions. CONCLUSIONS: This study demonstrate that gentamicin and clindamycin potentiated rocuronium induced neuromuscular blockade. Moreover, it was found that these drugs interacted synergistically.

Comparison of effects of fentanyl and remifentanil on hemodynamic response to endotracheal intubation and myoclonus in elderly patients with etomidate induction.

BACKGROUND: Etomidate has a stable hemodynamic profile after induction, but hypertension and tachycardia are frequent after intubation as well as myoclonus. We compared the effects of fentanyl and remifentanil on the hemodynamic response to intubation and myoclonus during etomidate induction in elderly patients. METHODS: Ninety ASA I or II patients aged over 65 were randomly assigned to 3 groups. Group C received normal saline 10 ml (n = 30), group F and R were pretreated with fentanyl 1.0 µg/kg (n = 30) or remifentanil 1.0 µg/kg with continuous infusion of 0.1 µg/kg/min (n = 30) 1 min before induction with etomidate 0.2 mg/kg. Endotracheal intubation was performed after administration of rocuronium 0.8 mg/kg. Systolic blood pressure (SBP), mean arterial pressure, diastolic blood pressure (DBP), heart rate (HR), and the incidence and intensity of myoclonus were recorded. RESULTS: After intubation, group R showed significant decreases compared with groups C and F for all of the hemodynamic variables measured. The incidences of increases in SBP and HR of more than 30% of the baseline levels, SBP of > 200 mmHg, and HR of > 120 beats/min were significantly lower in group R (0%, 10%, 0%, and 0%, respectively) compared with groups C (83%, 83%, 30%, and 13%, respectively) and F (63%, 77%, 13%, and 7%, respectively). The frequency and intensity of myoclonus were significantly decreased in both groups F and R compared with group C. CONCLUSIONS: Pretreatment with remifentanil suppressed cardiovascular reactions to endotracheal intubation more effectively than that of fentanyl during etomidate induction. Both opioids reduced the incidence of myoclonus.

The safety and efficacy of minimal-flow desflurane anesthesia during prolonged laparoscopic surgery.

BACKGROUND: Minimal-flow anesthesia can meet the demands of a modern society that is more sensitive to environmental protection and economic burdens. This study compared the safety and efficacy of minimal-flow desflurane anesthesia with conventional high-flow desflurane anesthesia for prolonged laparoscopic surgery. METHODS: Forty-six male patients (ASA physical status II or III) undergoing laparoscopic urologic surgery for more than 6 hours were randomly divided into two groups: the high-flow (HF) group and the minimal-flow (MF) group. The HF group was continuously administered a fresh gas flow of 4 L/min. In the MF group, a fresh gas flow of 4 L/min was administered for the first 20 minutes and was thereafter lowered to 0.5 L/min. Inspiratory and expiratory desflurane concentrations, respiratory variables, and hemodynamic variables were continuously monitored during administration of anesthesia. Measurements of carboxyhemoglobin (COHb) concentration and arterial blood gas analysis were performed every 2 hours during anesthesia. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine were measured on the first and second day after the surgery. RESULTS: Demographic data and duration of anesthesia were not different between the two groups. Significant differences were not observed between the two groups in terms of hemodynamic variables, respiratory variables, and inspiratory and expiratory desflurane concentrations. Inspiratory O(2) concentration was maintained lower in the MF group than in the HF group (43-53% vs. 53-59%; P < 0.05). Compared with the HF group, COHb concentrations was higher (P < 0.05), but not increased from the baseline value in the MF group. Serum AST, ALT, BUN, and creatinine were not significantly different between the two groups. CONCLUSIONS: In prolonged laparoscopic surgery, no significant differences were found in safety and efficacy between minimal-flow and high-flow desflurane anesthesia.

The antagonistic effect of neostigmine on rocuronium-, clindamycin-, or both-induced neuromuscular blocking in the rat phrenic nerve-hemidiaphragm.

BACKGROUND: Neostigmine augments clindamycin-induced neuromuscular block and antagonizes rocuronium-induced neuromuscular block; however, it remains unclear whether neostigmine enhances the neuromuscular blocking (NMB) that is caused by combinations of rocuronium and clindamycin. The intent of this study was to determine whether neostigmine potentiates the muscle relaxation that is induced by combinations of rocuronium and clindamycin and to estimate whether both clindamycin and rocuronium have synergistic actions on NMB. METHODS: Forty-one left phrenic nerve-hemidiaphragms (from male Sprague-Dawley rats, 150-250 g) were mounted in Krebs solution. Three consecutive single twitches (ST, 0.1 Hz) and one tetanic tension (50 Hz for 1.9 s) were obtained for each increase in concentration of rocuronium or clindamycin. The concentrations of rocuronium were cumulatively increased until an 80% to 90% reduction in ST was attained in the Krebs solutions pre-treated with 0 (n = 5), 0.1 (n = 1), 0.25 (n = 1), 0.5 (n = 4), or 1.0 (n = 1) mM clindamycin or with 0 (n = 4), 0.1 (n = 1), 0.5 (n = 5), 1.0 (n = 5), or 2.0 (n = 4) mM clindamycin in combination with 250 nM neostigmine, and so were the concentrations of clindamycin in the Krebs solutions pre-treated with 0 (n = 6) or 250 nM (n = 6) neostigmine. RESULTS: Clindamycin increased the potency of rocuronium for ST and tetanic fade, irrespective of the presence of neostigmine. Neostigmine shifted the concentration-response curve of rocuronium to the right in the presence or absence of clindamycin. The interaction between rocuronium and clindamycin was synergistic when clindamycin concentrations were in excess of 0.5 mM, irrespective of the presence of neostigmine. CONCLUSIONS: Neostigmine may partially antagonize the neuromuscular block that is induced by a combination of clindamycin and rocuronium. Clinicians are advised to be aware that clindamycin synergistically increases the degree of rocuronium-induced neuromuscular block, even when neostigmine is present.

Factors in patient dissatisfaction and refusal regarding spinal anesthesia.

BACKGROUND: Spinal anesthesia is the most common regional anesthesia conducted for many surgical procedures. Multiple factors can affect the success, the side effects, and patient satisfaction with the procedure. This study was undertaken prospectively to discover factors affecting dissatisfaction and refusal of spinal anesthesia. METHODS: Starting in December 2007, patients who underwent spinal anesthesia in the operating rooms of our hospital were surveyed over a period of a year. Before attempting the procedure, patient characteristics and previous history of anesthesia were recorded. Spinal anesthesia was administered with 0.5% heavy bupivacaine combined with fentanyl 0-20 µg. Intraoperative data and postoperative data on the day after surgery were collected. The patients were also asked about their general satisfaction with spinal anesthesia, causes of dissatisfaction with the procedure, and causes of their refusal to have spinal anesthesia again. RESULTS: Six patients among 1,197 cases were excluded from the study because of spinal anesthesia failure. The dissatisfaction rate of spinal anesthesia was 3.7%, and its risk factors were more than three puncture attempts, paresthesia at puncture, postoperative nausea and vomiting, and postoperative backache. The refusal rate to have spinal anesthesia again was 3.2%, and its risk factors were postoperative backache and dissatisfaction. CONCLUSIONS: Although spinal anesthesia was conducted safely during the study and revealed a high rate of patient satisfaction (96.3%), side effects still occurred. Therefore, attending anesthesiologists must perform the procedure carefully and always pay attention to patients under spinal anesthesia.

Effect of different anesthetic agents on oculocardiac reflex in pediatric strabismus surgery.

PURPOSE: The oculocardiac reflex (OCR) occurs frequently during pediatric strabismus surgery. The aim of this study was to assess the effects of various anesthetic regimens on the incidence of OCR during the surgery. METHODS: Two hundred and eighty children, 1 to 9 years old, undergoing elective strabismus surgery, were randomly assigned to eight groups; ketamine-sevoflurane (KS), ketamine-desflurane (KD), ketamine-propofol (KP), ketamine-remifentanil (KR), midazolam-sevoflurane (MS), midazolam-desflurane (MD), midazolam-propofol (MP), and midazolam-remifentanil (MR). No premedication was given. Anesthesia was induced using ketamine 1 mg kg(-1) or midazolam 0.15 mg kg(-1) with 66% N(2)O in O(2). Laryngeal mask airways (LMAs) were placed with rocuronium 0.5 mg kg(-1). Anesthesia was maintained with sevoflurane 2-3 vol. %, desflurane 5-6 vol. %, propofol 7-8 mg kg(-1) h(-1), or remifentanil 0.75 microg kg(-1) over 1 min, followed by a continuous infusion of remifentanil 0.5 microg kg(-1) min(-1) with 66% N(2)O in O(2). Heart rate (HR) was recorded during extraocular muscle (EOM) manipulation. OCR was defined as a reduction in HR of more than 20% induced by the traction of an EOM. RESULTS: In patients given ketamine, OCR occurred more frequently in the KP (65.7%) and KR (62.9%) groups than in the KD (29.4%) and KS (37.1%) groups (P < 0.05). In patients given midazolam, OCR occurred more frequently in the MP (54.3%) and MR (60.6%) groups than in the MD (36.4%) and MS (31.4%) groups (P < 0.05). CONCLUSION: Propofol or remifentanil anesthesia was associated with a higher incidence of OCR during pediatric strabismus surgery than sevoflurane and desflurane anesthesia, when either ketamine or midazolam was used as an induction agent.