Perioperative Extracorporeal Membrane Oxygenation Support for Acute Respiratory Distress Syndrome Aggravated by Hepatopulmonary Syndrome in Deceased Donor Liver Transplantation: A Case Report.

Background: Extracorporeal membrane oxygenation (ECMO) is an accommodation of the cardiopulmonary bypass technique that can support gas exchange and hemodynamic stability. It is used as a salvage maneuver in patients with life-threatening respiratory or cardiac failure that does not respond to conventional treatment. There are few case reports of successful perioperative use of ECMO, especially preoperatively, in liver transplantation (LT). Here, we report an experience of successful anesthetic management in deceased donor liver transplantation (DDLT) by applying perioperative veno-venous (VV) ECMO support in the setting of acute respiratory distress syndrome (ARDS) aggravated by hepatopulmonary syndrome (HPS). Case: A 25-year-old female (156.0 cm, 65.0 kg), without any underlying disease, was referred to our emergency department for decreased mentality. Based on imaging and laboratory tests, she was diagnosed with acute liver failure of unknown cause combined with severe ARDS aggravated by HPS. Since the patient faced life-threatening hypoxemia with a failure of conventional ventilation maneuvers, preoperative VV ECMO was initiated and maintained during the operation. The patient remained hemodynamically stable throughout DDLT, and ARDS showed gradual improvement after the administration of VV ECMO. As ARDS improved, the patient's condition alleviated, and VV ECMO was weaned on postoperative day 6. Conclusions: This case demonstrates that VV ECMO may be a useful therapeutic option not only during the intraoperative and postoperative periods but also in the preoperative period for patients with liver failure combined with reversible respiratory failure.

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.

Monitored anesthesia care with remimazolam for gynecological day surgeries: Case reports.

Remimazolam is a newly approved benzodiazepine characterized by rapid onset, predictable maintenance, fast recovery, and availability of a reversal agent. We describe four cases of patients who received monitored anesthesia care with remimazolam for gynecological day surgery.

Anesthetic Management of Upper Tracheal Cancer Resection and Reconstruction: A Case Report.

Tracheal tumor resection and reconstruction is the primary treatment for tracheal tumors. The trachea is the surgical site as well as an important channel to ensure ventilation and maintain oxygenation during surgery. In this report, we describe the successful management of an upper tracheal tumor in a 50-year-old patient. The tumor was situated approximately 2-3 cm below the vocal cords, occluding the tracheal lumen by 80%. Conventional orotracheal intubation was expected to be impossible, and the patient was managed with an I-Gel supraglottic airway for mechanical ventilation with the assistance of venovenous extracorporeal membrane oxygenation (VV ECMO). After securing tracheal intubation via the tracheostomy site, VV ECMO was weaned off, and mechanical ventilation was changed to tracheal intubation. Eventually, tracheal tumor resection and reconstruction were successfully performed under general anesthesia. No specific events occurred during anesthetic management. Careful preoperative planning and good teamwork made the procedure possible without complications.

No Difference between Spinal Anesthesia with Hyperbaric Ropivacaine and Intravenous Dexmedetomidine Sedation with and without Intrathecal Fentanyl: A Randomized Noninferiority Trial.

To enhance the duration of single-shot spinal anesthesia, intrathecal fentanyl and intravenous dexmedetomidine are widely used as adjuvants to local anesthetics. This noninferiority trial evaluated whether hyperbaric ropivacaine alone can produce a noninferior duration of sensory block in comparison to hyperbaric ropivacaine with intrathecal fentanyl in patients under dexmedetomidine sedation. Methods. Fifty patients scheduled for elective lower limb surgery under spinal anesthesia were randomly assigned in a double-blind fashion to receive either hyperbaric ropivacaine 15 mg (Group R) or hyperbaric ropivacaine 15 mg with intrathecal fentanyl 20 µg (Group RF). Intravenous dexmedetomidine (1 µg/kg for 10 min, followed by 0.5 µg/kg/h) was administered in both groups. The primary outcome of this study was the time to two-dermatomal regression of sensory block. The noninferiority margin for the mean difference was -10 min. Characteristics of the block, intraoperative and postoperative side effects, postoperative pain score, and analgesic consumption were assessed as secondary outcomes. Results. There was no difference in the two-dermatomal regressions of sensory block between the two groups (Group R 70.4 ± 10.2 min, Group RF 71.2 ± 12.4 min, p = 0.804) with a mean difference of 0.8 min (-7.2 to 5.6, 95% confidence interval). Thus, the noninferiority of hyperbaric ropivacaine alone was established. There were no significant differences in the secondary outcomes between the two groups. Conclusions. Under intravenous dexmedetomidine sedation, the duration of spinal anesthesia with hyperbaric ropivacaine alone was noninferior to that of hyperbaric ropivacaine with intrathecal fentanyl. This suggests that addition of intrathecal fentanyl to hyperbaric ropivacaine may not be necessary in patients receiving intravenous dexmedetomidine.

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 of neuromuscular blockade recovery co-administered with neostigmine and different doses of calcium gluconate: a randomized control trial.

BACKGROUND: Calcium increases the probability of transmitter release at the neuromuscular junction. It is not known whether there is a dose-dependent relationship between the dosage of calcium gluconate and the probability of transmitter release for non-depolarizing neuromuscular blockade (NMB) recovery by acetylcholinesterase inhibitors (AchEIs). This study compared the neuromuscular recovery time and the incidence of postoperative residual curarization (PORC) according to the dosage of calcium gluconate co-administered with neostigmine in three patient groups. METHODS: Patients were randomly allocated to a control group, a 5 mg/kg calcium gluconate group (calcium 5 group), or a 10 mg/kg calcium gluconate group (calcium 10 group). In patients with a TOF ratio (TOFr) between 0.2-0.7, 0.04 mg/kg of neostigmine was administered and both 0.2 mg of glycopyrrolate and 0.4 mg of atropine per 1 mg of neostigmine were administered. And additional 5 or 10 mg/kg of calcium gluconate were administrated to the calcium 5 and 10 groups. The primary endpoint was neuromuscular recovery time (the time between reversal and TOFr≥0.9). The secondary endpoints were the incidence of PORC at 5, 10, and 20 min after reversal administration and the train-of-four ratio (TOFr) at each time point. RESULTS: The neuromuscular recovery time was 5.3 min in the control group, 3.9 min in the calcium 5 group, and 4.1 min in the calcium 10 group, respectively (P = 0.004). The incidence of PORC at 5 min after neostigmine administration was 12 in the control group, 4 in the calcium 5 group, and 4 in the calcium 10 group, respectively, with statistical significance (P = 0.014). CONCLUSIONS: The co-administration of calcium gluconate with neostigmine safely promoted early NMB recovery, and the neuromuscular recovery time of the calcium 10 group tended to be more evenly distributed than that of the calcium 5 group. TRIAL REGISTRATION: https://cris.nih.go.kr/cris/index.jsp(KCT0004182 ). Date of registration: August 122,019.

A Low Dose of Naloxone Added to Ropivacaine Prolongs Femoral Nerve Blockade: A Randomized Clinical Trial.

Femoral nerve blocks (FNBs) are used as safe and useful procedures to control severe postoperative pain from total knee arthroplasty (TKA). Various adjuvants have been used to prolong the duration of the local anesthetic blockade. This study evaluated whether a low dose of naloxone administered with local anesthetics prolongs the duration of FNB. A prospective, randomized double-blind controlled study was conducted with 74 patients undergoing unilateral TKA. Through a single-bolus administration guided by ultrasound, the control group (group C) received 20 mL of 0.375% ropivacaine, while the naloxone group (group N) received 20 mL of 0.375% ropivacaine with 100 ng of naloxone. The time elapsed before the first analgesia request, the total amount of opioids consumed at 24 h postoperatively, the onset time of the sensory blockade, the visual analog pain scale (VAS) scores after arriving at the recovery room, after 6, 12, 18, and 24 h at rest and after 12, 18, and 24 h of activity, the quadricep strength before the FNB procedure and at 12 and 24 h postoperatively, the quality of sleep on the first night after surgery, the satisfaction score, and the incidence of postoperative complications were recorded. The time elapsed before the first analgesia request was significantly longer in group N (735.5 ± 187.2 min) than that in group C (602.6 ± 210.4 min) (P=0.003). The total dose of supplementary opioids consumed at 24 h postoperatively was significantly lower in group N (312.4 ± 141.7 µg) than that in group C (456.5 ± 279.5 µg) (P=0.007). Lower VAS scores were recorded in group N than that in group C at rest and during knee activity (rest, 12 h, P=0.001, 18 h, P=0.043; activity, 12 h, P=0.001). The addition of a low dose of naloxone to ropivacaine for FNB significantly delayed the first request for rescue analgesia and decreased the opioid consumption within 24 h, without significant complications.

Comparison of postoperative pulmonary complications between sugammadex and neostigmine in lung cancer patients undergoing video-assisted thoracoscopic lobectomy: a prospective double-blinded randomized trial.

BACKGROUND: Reversal of neuromuscular blockade (NMB) at the end of surgery is important for reducing postoperative residual NMB; this is associated with an increased risk of postoperative pulmonary complications (PPCs). Moreover, PPCs are associated with poor prognosis after video-assisted thoracoscopic surgery (VATS) for lobectomy. We compared the effects of two reversal agents, sugammadex and neostigmine, on the incidence of PPCs and duration of hospital stay in patients undergoing VATS lobectomy. METHODS: After VATS lobectomy was completed under neuromuscular monitoring, the sugammadex group (n = 46) received sugammadex 2 mg/kg, while the neostigmine group (n = 47) received neostigmine 0.05 mg/kg with atropine 0.02 mg/kg after at least the third twitch in response to the train of four stimulation. The primary outcome was incidence of PPCs. The secondary outcomes were duration of hospital stay and intensive care unit (ICU) admission. RESULTS: There was no significant difference in the incidence of PPCs for both the sugammadex and neostigmine groups (32.6% and 40.4%, respectively; risk difference = 0.08; 95% confidence interval = [-0.12, 0.27]; P = 0.434). The lengths of hospital (P = 0.431) and ICU (P = 0.964) stays were not significantly different between the two groups. CONCLUSIONS: The clinical use of sugammadex and neostigmine in NMB reversal for patients undergoing VATS lobectomy was not significantly different in the incidence of PPCs and duration of hospital and ICU stay.

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.

Anesthetic considerations during surgical intervention in Woake's syndrome -a case report.

BACKGROUND: Woake's syndrome (WS) is a recurrent nasal polyposis, accompanied by broadening of the nose, frontal sinus aplasia, dyscrinia, and bronchiectasis. There has been no previous report on anesthetic management in patients with WS. CASE: We describe a case involving a 13-year-old male patient with WS who was scheduled for septorhinoplasty for necrotic ethmoiditis. Anesthesia was induced and maintained with propofol and remifentanil using a target-controlled infusion device. The anesthetic considerations of this rare syndrome and the advantages of an intravenous infusion method over local and volatile anesthesia for these patients are discussed. We report on caveats, such as pulmonary dysfunction during the anesthetic management, and nasal structural problems encountered in WS patients. CONCLUSIONS: Given that conventional inhaled anesthesia reduces ciliary movement and that local anesthesia with sedative has several disadvantages, perioperative control and precautions against respiratory infections by using antibiotics, and preventing cilio-depressant actions, are important for anesthetic management.

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.

Use of sugammadex in lung cancer patients undergoing video-assisted thoracoscopic lobectomy.

BACKGROUND: This study aimed to retrospectively evaluate the use of sugammadex in patients undergoing video-assisted thoracoscopic surgery (VATS) lobectomy. METHODS: Data were obtained from medical record review of patients who underwent VATS lobectomy from January 2013 to November 2014. Fifty patients were divided into two groups: the sugammadex group (group S, n = 19) was administered sugammadex 2 mg/kg, while the pyridostigmine group (group P, n = 31) received pyridostigmine 20 mg with glycopyrrolate 0.2 mg or atropine 0.5 mg. The primary endpoint measure was the overall incidence of postoperative pulmonary complications including prolonged air leak, pneumonia, and atelectasis. The secondary endpoint measures were the length of postoperative hospital stay and duration of chest tube insertion. RESULTS: The overall incidence of postoperative pulmonary complications in patients in group S was significantly lower compared with that of group P (5 [26.3%] vs. 17 [54.8%]; P = 0.049). Also, the durations of chest tube insertion (5.0 [4.0-7.0] vs. 7.0 [6.0-8.0] days; P = 0.014) and postoperative hospital stay (8.0 [8.0-10.0] vs. 10.0 [9.0-11.0] days; P = 0.019) were shorter in group S compared with group P. Administration of sugammadex was associated reduced with postoperative pulmonary complications (OR: 0.22; 95% CI: 0.05-0.87; P = 0.031). CONCLUSIONS: The use of sugammadex, compared with pyridostigmine, showed a significantly reduced overall incidence of postoperative pulmonary complications and decreased duration of chest tube use and postoperative hospital stay in patients undergoing VATS lobectomy, suggesting that sugammadex might be helpful in improving clinical outcomes in such patients.

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.

The effect of high concentration of magnesium with ropivacaine, gentamicin, rocuronium, and their combination on neuromuscular blockade.

BACKGROUND: Magnesium, ropivacaine, gentamicin, and rocuronium block neuromuscular (NM) transmission by different mechanisms. Therefore, concurrent administration of these agents may induce prolonged muscle paralysis via synergistic interaction. This study investigated the efficacy and safety of NM block caused by the administration of high concentrations of magnesium in combination with ropivacaine, gentamicin, and rocuronium. METHODS: Eighty-three left phrenic nerve-hemidiaphragms from male SD rats (150-250 g) were hung in Krebs solution. Three consecutive single twitch tension (ST, 0.1 Hz) and one tetanic tension (TT, 50 Hz for 1.9 s) were obtained before drug application and at each new drug concentration. The concentration of MgCl2 and MgSO4 in Krebs solution was increased until an 80 to 90% reduction in ST was reached. To test the effects of combinations of NM agents, a Krebs solution was premixed with MgCl2 alone, MgCl2 and ropivacaine, or MgCl2, ropivacaine, and gentamicin. The concentration of ropivacaine, gentamicin, or rocuronium was then progressively increased until an 80 to 90% reduction in ST was reached. The effective concentrations were estimated with a probit model. RESULTS: The potency of MgCl2 was greater than that of MgSO4, and pretreatment with MgCl2 increased the potency of gentamicin and rocuronium. Unexpectedly, MgCl2 did not potentiate ropivacaine, and the potency of gentamicin and rocuronium failed to show an increase when premixed with 0.5 µM ropivacaine. CONCLUSIONS: The concomitant administration of high concentrations of magnesium and ropivacaine together with clinically relevant concentrations of gentamicin or rocuronium potentiated NM blockade but not with clinically relevant concentrations of ropivacaine.

Effect of ketamine and midazolam on oculocardiac reflex in pediatric strabismus surgery.

BACKGROUND: The oculocardiac reflex (OCR) can be elicited during manipulation of the orbital structures in the strabismus correction surgery. A sinus bradycardia is the most common manifestation of OCR; and cardiac dysrhythmia and asystole may also occur. Various efforts to reduce OCR have been attempted, but without coherent outcome results. METHODS: Sixty one children, undergoing elective strabismus surgery, were randomly allocated into 2 groups: Group K received ketamine 1.0 mg/kg; and Group M received midazolam 0.15 mg/kg for induction of anesthesia. Anesthesia was maintained with 1-1.3 MAC of sevoflurane with 50% N2O in O2. Heart rate and blood pressure were measured 30 seconds before extraocular muscle (EOM) traction and immediately after traction. The OCR was defined as a decrease in heart rate more than 20% of the baseline heart rate, following manipulating EOM. Postoperative nausea and vomiting (PONV) and emergence agitation (EA) were assessed in postanesthetic care unit (PACU). RESULTS: Blood pressure before tightening EOM in Group K was higher than that in Group M (P < 0.05). However Δ HR (2.7 ± 15% vs. - 0.9 ± 16%) and incidence of OCR (10.0% vs. 19.4%) after traction an EOM were not different between the two groups. The occurrence of PONV (6.7 vs. 9.7%) and EA (30.0% vs. 22.6%) were similar. CONCLUSIONS: Ketamine does not reduce the incidence of OCR compared with midazolam in pediatric strabismus surgery. In addition, ketamine does not increase the incidence of PONV and EA. In conclusion, it is reliable to use ketamine in pediatric strabismus surgery.

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.