Effect of preoperative oral rehydration before cesarean section on ultrasound assessment of gastric volume and intraoperative hemodynamic changes: a randomized controlled trial.

BACKGROUND: Cesarean section often requires an urgent transfusion load due to decreased blood pressure after spinal anesthesia. This prospective randomized study aimed to investigate whether a preoperative oral rehydration solution (ORS) stabilized perioperative circulatory dynamics. METHODS: Sixty-three parturients scheduled for cesarean section under combined spinal epidural anesthesia (CSEA) were randomly allocated to one of three groups: Group O received 500 mL ORS before bedtime and 500 mL 2 h before CSEA; Group M received mineral water instead of ORS; and Group C had no fluid intake (controls). After entering the operating room, stomach size was measured using ultrasound. Blood samples were obtained, and CSEA was induced. Vasopressors were administered when systolic blood pressure was < 90 mmHg or decreased by > 20%. As a vasopressor, phenylephrine (0.1 mg) was administered at ≥ 60 beats/min heart rate or ephedrine (5 mg) at < 60 beats/min heart rate. The primary outcome was the total number of vasopressor boluses administered. Secondary outcomes were the cross-sectional area of the stomach antrum, maternal plasma glucose levels, serum sodium levels, total intravenous fluid, bleeding volume, urine volume, operative time, and cord blood gas values after delivery. RESULTS: The total number of vasopressor boluses was lower in Group O than in Group C (P < 0.05). Group O had lower total dose of phenylephrine than Group C (P < 0.05). There were no significant differences between Group M and other groups. No differences were detected regarding secondary outcomes. CONCLUSIONS: In women scheduled for cesarean section, preoperative ORS stabilized perioperative circulatory dynamics. Neither ORS nor mineral water consumption increased the stomach content volume. TRIAL REGISTRATION: This trial is registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000019825: Date of registration 17/11/2015).

Comparison of a new EMG module, AF-201P, with acceleromyography using the post-tetanic counts during rocuronium-induced deep neuromuscular block: a prospective, multicenter study.

Recent advances in neuromuscular monitors have facilitated the development of a new electromyographic module, AF-201P™. The purpose of this study was to investigate the relationship between post-tetanic counts (PTCs) assessed using the AF-201P™ and the acceleromyographic TOF Watch SX™ during rocuronium-induced deep neuromuscular block. Forty adult patients consented to participate in this study. The integrated AF-201P™ stimulating and sensing electrode was placed over the ulnar nerve on the distal volar forearm and the belly of the abductor digiti minimi muscle of one arm. The TOF Watch SX™ was applied with the provided hand adaptor on the opposite arm, to observe twitch responses of the adductor pollicis muscle. After stabilization of train-of-four (TOF) responses, rocuronium 0.9 mg kg-1 was administered intravenously. Then, PTCs were observed every 3 min using both monitors. Whenever the TOF count was detected with the TOF Watch SX™, rocuronium 0.2 mg kg-1 was administered, and successive PTC measurements were continued. A total of 1732 paired PTC data points were obtained and analyzed. Regression analysis showed no significant difference in PTCs between the two monitors (PTCs measured by the TOF Watch SX™ = 0.78·PTCs measured by AF-201P™ + 0.21, R = 0.56). Bland-Altman analysis also showed acceptable ranges of bias [95% CI] and limits of agreement (0.3 [0.2 to 0.5] and - 4.6 to 5.3) for the PTCs. The new EMG module, AF-201P™, showed reliable PTCs during deep neuromuscular block, as well as the TOF Watch SX™.

Use of intraoperative neuromuscular monitor reduces the reversal dose of sugammadex: a single-center retrospective study.

PURPOSE: We compared the reversal doses of sugammadex in surgical cases in which intraoperative neuromuscular monitor were used, to cases in which intraoperative neuromuscular monitoring was not used, retrospectively. METHODS: Data were collected by reviewing the electronic medical records of patients who received rocuronium and sugammadex during general anesthesia at Asahikawa Medical University Hospital between May 1, 2017 and April 30, 2018. The primary outcome was the reversal dose of sugammadex per patient actual body weight (mg/kg) between the group in which intraoperative neuromuscular monitoring was used (NM+ group) and the group in which intraoperative neuromuscular monitoring was not used (NM- group). RESULTS: A total of 3496 patients were evaluated, with 2544 patients (73%) included in NM+ group and 952 patients (27%) in NM- group. The reversal doses of sugammadex per actual body weight were significantly higher in NM- group compared to NM+ group. In the NM+ group, 521 patients (20%) received < 2 mg/kg sugammadex, 1377 patients (54%) received 2 ~ 2.5 mg/kg sugammadex, and 646 patients (25%) received > 2.5 mg/kg sugammadex. In contrast, 128 patients (13%) received < 2 mg/kg sugammadex, 362 patients (38%) received 2 ~ 2.5 mg/kg sugammadex and 462 patients (49%) received > 2.5 mg/kg sugammadex in NM- group. CONCLUSION: This single-center retrospective study demonstrated that the use of intraoperative neuromuscular monitor reduced the reversal dose of sugammadex.

Effectiveness and Safety of Ultrasound Guided Lower Extremity Nerve Blockade in Infragenicular Bypass Grafting for High Risk Patients With Chronic Limb Threatening Ischaemia.

OBJECTIVES: Surgical revascularisation to accomplish limb salvage remains preferable in some patients with chronic limb threatening ischaemia (CLTI). The aim of this study was to evaluate the effectiveness and safety of ultrasound guided lower extremity nerve blockade (UGNB) in infragenicular bypass surgery (IGBS). METHODS: This was a single centre, retrospective clinical study. Fifty-nine patients with CLTI (67 limbs) who underwent IGBS under UGNB (femoral and sciatic nerve blockade) at Asahikawa Medical University between January 2012 and December 2017 were compared with patients with CLTI (137 limbs) who underwent IGBS under general anaesthesia (GA) over the same period. Propensity score matching based on pre-operative comorbidities was used to minimise background differences of the two groups. RESULTS: Fifty-six pairs of CLTIs were matched and analysed (55% dialysis dependent). Procedure duration was similar between the two groups, but intraoperative catecholamine index and intravenous fluid volume were lower with UGNB compared with GA (2.9 ± 4.6 vs. 5.9 ± 6.5; p < .01 and 1831 ± 990 vs. 2335 ± 931 mL; p < .01, respectively). The mean arterial blood pressure during induction of anaesthesia was significantly decreased with GA. Post-operatively, the time period to resume a clear liquid and solid food diet was significantly shorter with UGNB (P<0.01 for both outcome measures). Intravenous fluid volume was significanlty lower, while cardiac complications and delirium, based on the NEECHAM confusion scale, occurred significantly less often with UGNB than GA. These significant differences show advantages of UGNB compared to GA. No mortality or major amputations were observed in either group. Early graft thrombosis was observed in five limbs (8.9%) with UGNB and in four limbs with GA (7.1%) (p = .73). CONCLUSIONS: UGNB has advantages for intra- and post-operative management and could be a useful method to prevent peri-operative complications for high risk patients with CLTI. To ensure the effectiveness of UGNB for IGBS for future indications, a randomised study is required.

GTS-21 attenuates loss of body mass, muscle mass, and function in rats having systemic inflammation with and without disuse atrophy.

Muscle changes of critical illness are attributed to systemic inflammatory responses and disuse atrophy. GTS-21 (3-(2,4-dimethoxy-benzylidene)anabaseine), also known as DMBX-A) is a synthetic derivative of the natural product anabaseine that acts as an agonist at α7-acetylcholine receptors (α7nAChRs). Hypothesis tested was that modulation of inflammation by agonist GTS-21 (10 mg/kg b.i.d. intraperitoneally) will attenuate body weight (BW) and muscle changes. Systemic sham inflammation was produced in 125 rats by Cornyebacterium parvum (C.p.) or saline injection on days 0/4/8. Seventy-four rats had one immobilized-limb producing disuse atrophy. GTS-21 effects on BW, tibialis muscle mass (TMM), and function were assessed on day 12. Systemically, methemoglobin levels increased 26-fold with C.p. (p < 0.001) and decreased significantly (p < 0.033) with GTS-21. Control BW increased (+ 30 ± 9 g, mean ± SD) at day 12, but decreased with C.p. and superimposed disuse (p = 0.005). GTS-21 attenuated BW loss in C.p. (p = 0.005). Compared to controls, TMM decreased with C.p. (0.43 ± 0.06 g to 0.26 ± 0.03 g) and with superimposed disuse (0.18 ± 0.04 g); GTS-21 ameliorated TMM loss to 0.32 ± 0.04 (no disuse, p = 0.028) and to 0.22 ± 0.03 (with disuse, p = 0.004). Tetanic tensions decreased with C.p. or disuse and GTS-21 attenuated tension decrease in animals with disuse (p = 0.006) and in animals with C.p. and disuse (p = 0.029). C.p.-induced 11-fold increased muscle α7nAChR expression was decreased by > 60% with GTS-21 treatment. In conclusion, GTS-21 modulates systemic inflammation, evidenced by both decreased methemoglobin levels and decrease of α7nAChR expression, and mitigates inflammation-mediated loss of BW, TMM, fiber size, and function.

Duration of the action of rocuronium in patients with BMI of less than 25: An observational study.

BACKGROUND: The duration of rocuronium in patients with BMI more than 30 kg m is prolonged. Whether the reverse is true when BMI is less than 18.5 kg m is unclear. OBJECTIVE: The objective of this study was to investigate whether a BMI less than 25 kg m affects the duration of rocuronium in doses adjusted for actual body weight. DESIGN: A prospective, observational, single-centre study. SETTING: The operating room of a teaching hospital from 1 June 2008 to 30 June 2015. PATIENTS: Thirty patients with American Society of Anesthesiologists physical status I or II who were scheduled to undergo elective surgery (BMI < 25 kg m, aged 23 to 74 years) maintained by 0.7 minimum alveolar concentration sevoflurane and remifentanil. MAIN OUTCOME MEASURES: Repetitive train-of-four stimulation was applied and contractions of the adductor pollicis muscle were recorded. Duration of the initial dose of rocuronium (D1) was defined as the time from injection of rocuronium 0.6 mg kg to return of first twitch height to 25% of the control. Duration of additional doses (D2) was the time from a supplement of 0.15 mg kg rocuronium to return of first twitch height to 25% of the control. The relationship between D1 or D2 and BMI was examined using linear regression analysis. RESULTS: Linear regression analysis revealed a significant correlation between duration of initial dose and BMI (R = 0.246; P = 0.00531). A significant correlation between the duration of the additional dose and BMI was also found (R = 0.316; P = 0.00122). CONCLUSION: The lower the BMI, the shorter the duration of rocuronium at initial and additional doses determined by the actual body weight in adult patients with a BMI less than 25 kg m. TRIAL REGISTRATION: www.umin.ac.jp/ctr/index/htm with registry number UMIN 00009337 and UMIN 000015407.

Ultrasound-guided lumbar plexus block using three different techniques: a comparison of ultrasound image quality.

PURPOSE: The purpose of this study was to compare the ultrasound image quality at three different transducer positions for ultrasound-guided lumbar plexus block (LPB). METHODS: This prospective comparative study included 30 patients who underwent total hip arthroplasty under general anesthesia in combination with LPB. Using the same ultrasound machine settings for each patient, a transverse view of the lumbar plexus (LP) at the L3-4 vertebral level was obtained with a convex transducer placed at three different positions: immediately lateral to the dorsal midline (medial position), almost 5 cm lateral to the dorsal midline (paravertebral position), and at the abdominal transverse flank (shamrock position). Ultrasound-guided LPB with catheter insertion was performed via in-plane needle insertion with the transducer randomly assigned to one of the three positions. The echo intensity (EI) ratio of the LP to psoas major muscle (PMM), the EI of the LP and PMM, and the ultrasound visibility score of the needle, local anesthetic, and catheter were recorded. RESULTS: The LP/PMM EI ratio was significantly higher at paravertebral position (1.4 ± 0.2) than at medial position (1.2 ± 0.2; p = 0.003) and shamrock position (1.3 ± 0.2; p = 0.040). The EI of the LP and PMM was highest at shamrock position (p < 0.001). During the block procedure, the ultrasound visibility score of the needle and local anesthetic was significantly higher at paravertebral position than at medial position. CONCLUSION: Under the conditions of this study, the contrast between LP and PMM is significantly higher at paravertebral position than at medial position and at the abdominal transverse flank (shamrock position). LP and PMM at the shamrock position appear significantly brighter among the three probe positions in sonograms.

Comparison of caudal ropivacaine-morphine and paravertebral catheter for major upper abdominal surgery in infants.

BACKGROUND: The caudal epidural block is one of the most commonly used regional anesthetic techniques in children. Administration of morphine via caudal injection enables analgesia, even for upper abdominal surgery. The thoracic paravertebral block has also been successfully used to treat perioperative pain during upper abdominal procedures in pediatric patients. AIM: In the current study, we compared the two regional techniques for upper abdominal surgery in infants to determine whether one of them was preferable to the other. METHODS: Consecutive patients under 12 months of age who underwent upper abdominal surgery were retrospectively divided according to the chosen postoperative analgesia: Group C, caudal ropivacaine-morphine; Group P, paravertebral catheter. We analyzed the following outcomes: requirement for additional analgesics, pain scores, need for mechanical ventilation and oxygen dosage, postoperative blood pressure and heart rate, time to pass first stool, time until first full meal, and complications. RESULTS: Twenty-one consecutive patients were included: 10 in Group C and 11 in Group P. Median age at surgery was 80 (47.5-270.0) and 84.5 (34.3-287.5) days, respectively. No difference was found between the two groups in requirement for additional analgesics at 24 h after surgery (median 1 in Group C vs 1 in Group P, P = 0.288, 95% CI: -2 to 1). BOPS pain scores were only lower in Group P when compared to Group C at 24 h after surgery (median 1 vs 2, P = 0.041, 95% CI: -2 to 0). None of the patients had perioperative complications. CONCLUSIONS: In this small series, there was no significant difference between caudal ropivacaine-morphine and paravertebral catheter for postoperative care in infants undergoing upper abdominal surgery. Further prospective studies are needed to compare the efficacy and incidence of complications of caudal block and paravertebral catheter for postoperative analgesia.

The predictive ability of six pharmacokinetic models of rocuronium developed using a single bolus: evaluation with bolus and continuous infusion regimen.

PURPOSE: Rocuronium concentration prediction using pharmacokinetic (PK) models would be useful for controlling rocuronium effects because neuromuscular monitoring throughout anesthesia can be difficult. This study assessed whether six different compartmental PK models developed from data obtained after bolus administration only could predict the measured plasma concentration (Cp) values of rocuronium delivered by bolus followed by continuous infusion. METHODS: Rocuronium Cp values from 19 healthy subjects who received a bolus dose followed by continuous infusion in a phase III multicenter trial in Japan were used retrospectively as evaluation datasets. Six different compartmental PK models of rocuronium were used to simulate rocuronium Cp time course values, which were compared with measured Cp values. Prediction error (PE) derivatives of median absolute PE (MDAPE), median PE (MDPE), wobble, divergence absolute PE, and divergence PE were used to assess inaccuracy, bias, intra-individual variability, and time-related trends in APE and PE values. RESULTS: MDAPE and MDPE values were acceptable only for the Magorian and Kleijn models. The divergence PE value for the Kleijn model was lower than -10 %/h, indicating unstable prediction over time. The Szenohradszky model had the lowest divergence PE (-2.7 %/h) and wobble (5.4 %) values with negative bias (MDPE = -25.9 %). These three models were developed using the mixed-effects modeling approach. The Magorian model showed the best PE derivatives among the models assessed. CONCLUSIONS: A PK model developed from data obtained after single-bolus dosing can predict Cp values during bolus and continuous infusion. Thus, a mixed-effects modeling approach may be preferable in extrapolating such data.

A case series of re-establishment of neuromuscular block with rocuronium after sugammadex reversal.

We report the use of rocuronium to re-establish neuromuscular block after reversal with sugammadex. The aim of this study was to investigate the relationship between the dose of rocuronium needed to re-establish neuromuscular block and the time interval between sugammadex administration and re-administration of rocuronium. Patients who required re-establishment of neuromuscular block within 12 h after the reversal of rocuronium-induced neuromuscular block with sugammadex were included. After inducing general anesthesia and placing the neuromuscular monitor, the protocol to re-establish neuromuscular block was as follows. An initial rocuronium dose of 0.6 mg/kg was followed by additional 0.3 mg/kg doses every 2 min until train-of-four responses were abolished. A total of 11 patients were enrolled in this study. Intervals between sugammadex and second rocuronium were 12-465 min. Total dose of rocuronium needed to re-establish neuromuscular block was 0.6-1.2 mg/kg. 0.6 mg/kg rocuronium re-established neuromuscular block in all patients who received initial sugammadex more than 3 h previously. However, when the interval between sugammadex and second rocuronium was less than 2 h, more than 0.6 mg/kg rocuronium was necessary to re-establish neuromuscular block.

[Evaluation of the Effects of Remifentanil Doses on Hemodynamics and Perfusion Index at the Onset of Pneumoperitoneum during Laparoscopic Surgery].

BACKGROUND: The aim of this study was to investigate whether changes in perfusion index (PI) correlate with non-invasive haemodynamic parameters (HR, BP) following the onset of pneumoperitoneum under two doses (moderate-dose (MD) and high-dose (HD)) of remifentanil and to compare its reliability. METHODS: We divided 33 patients who were scheduled for laparoscopic surgery under general anesthesia into two groups according to the dose of continuously infused remifentanil: moderate dose 0.5 µg x kg(-1) x min(1) (MD group, n = 16) and high dose 1.0 µg x kg(-1) x min(-1) (HD group, n = 17). Non-invasive blood pressure (NIBP), HR, and PI were measured before the start of surgery (time 1), after the start of surgery (time 2), before the start of pneumoperitoneum (time 3), and 1 min after the stable state of pneumoperitoneum (time 4). RESULTS: PI decreased from the baseline after pneumoperitoneum in MD group, on the other hand PI did not change in HD group. Between the two groups, the magnitude of the PI changes was statistically different although MBP and HR were not statistically different CONCLUSIONS: PI may be a reliable and easier alternative to conventional haemodynamic parameters for detection of stress response to pneumoperitoneum during remifentanil anaesthesia in adult patients.

[The Distance between the Sciatic Nerve Bifurcation and Popliteal Fossa in Japanese].

BACKGROUND: The bifurcation into tibial nerve and common peroneal nerve is generally targeted for sciatic nerve block at popliteal approach. However, it is sometimes difficult to determine the exact bifurcation point in clinical situation. The mean distance between the popliteal fossa and division of sciatic nerve (DPDSN) was reported approximately 6 cm ± 2.5 cm in Caucasian cadaver study. We also studied DPDSN in Japanese cadaver to find ethnic difference. METHODS: We dissected and recorded DPDSN and distance from gluteal fold to heel (foot length : FL) in 15 cadavers. RESULTS: Mean DPDSN was 2.46 ± 2.00 cm (range: 0 to 8.8 cm). The DPDSN and FL were not correlated. CONCLUSIONS: DPDSN of Japanese cadaver is shorter than the previously reported data in Caucasian cadaver. Since the DPDSN has inter-individual and intra-individual differences, we should estimate the DPDSN carefully in each leg using ultrasonography and nerve stimulator.

Immobilization with atrophy induces de novo expression of neuronal nicotinic α7 acetylcholine receptors in muscle contributing to neurotransmission.

BACKGROUND: Mature acetylcholine receptor (AChR) isoform normally mediates muscle contraction. The hypothesis that α7AChRs up-regulate during immobilization and contribute to neurotransmission was tested pharmacologically using specific blockers to mature (waglerin-1), immature (αA-OIVA), and α7AChRs (methyllycaconitine), and nonspecific muscle AChR antagonist, α-bungarotoxin. METHODS: Mice were immobilized; contralateral limbs were controls. Fourteen days later, anesthetized mice were mechanically ventilated. Nerve-stimulated tibialis muscle contractions on both sides were recorded, and blockers enumerated above sequentially administered via jugular vein. Data are mean ± standard error. RESULTS: Immobilization (N = 7) induced tibialis muscle atrophy (40.6 ± 2.8 vs. 52.1 ± 2.0 mg; P < 0.01) and decrease of twitch tension (34.8 ± 1.1 vs. 42.9 ± 1.5 g; P < 0.01). Waglerin-1 (0.3 ± 0.05 µg/g) significantly (P = 0.001; N = 9) depressed twitch tension on contralateral (≥97%) versus immobilized side (approximately 45%). Additional waglerin-1 (total dose 1.06 ± 0.12 µg/g or approximately 15.0 × ED50 in normals) could not depress twitch of 80% or greater on immobilized side. Immature AChR blocker, αA-OIVA (17.0 ± 0.25 µg/g) did not change tension bilaterally. Administration of α-bungarotoxin (N = 4) or methyllycaconitine (N = 3) caused 96% or greater suppression of the remaining twitch tension on immobilized side. Methyllycaconitine, administered first (N = 3), caused equipotent inhibition by waglerin-1 on both sides. Protein expression of α7AChRs was significantly (N = 3; P < 0.01) increased on the immobilized side. CONCLUSIONS: Ineffectiveness of waglerin-1 suggests that the twitch tension during immobilization is maintained by receptors other than mature AChRs. Because αA-OIVA caused no neuromuscular changes, it can be concluded that immature AChRs contribute minimally to neurotransmission. During immobilization approximately 20% of twitch tension is maintained by up-regulation of α-bungarotoxin- and methyllycaconitine-sensitive α7AChRs.

Nonsurgically induced disuse muscle atrophy and neuromuscular dysfunction upregulates alpha7 acetylcholine receptors.

Previous models of muscle disuse have invariably used surgical methods that require the repetitive application of plaster casts. A method of disuse atrophy that does not require such repetitive applications is described herein. Modified plastic pipette tubing was applied to a single hindlimb (mouse), from thigh to foot, resulting in immobilization of the knee in the extension position, and the ankle in the plantar flexion position. This method resulted in the loss of soleus muscle to 11%, 22%, 39%, and 45% of its original mass at 3, 7, 14, and 21 days, respectively, in association with a significant decrease of tibialis twitch (25%) and tetanic tensions (26%) at 21 days, compared with the contralateral side and (or) sham-immobilized controls. Immunohistochemical analysis of the soleus using fluorescent α-bungarotoxin revealed a significant increase in the number of synapses per unit area (818 + 31 compared with 433 + 16/mm(2)) and an increase in muscle fibers per unit area (117 compared with 83/mm(2)), most likely related to the atrophy of muscle fibers bringing synapses closer. A 3-fold increase in alpha7 acetylcholine receptor (α7AChR) protein expression, along with increased expression of α1AChR subunit in the immobilized side compared with the contralateral side was observed. The physiology and pharmacology of the novel finding of upregulation of α7AChRs with disuse requires further study.

A temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in a pediatric patient.

We report a temporary decrease in twitch response following reversal of rocuronium-induced neuromuscular block with a small dose of sugammadex in our dose-finding study in pediatric patients. A 19-month-old female infant (9.6 kg, 80 cm) was scheduled for elective cheiloplasty surgery. Anesthesia was induced with nitrous oxide 50% and sevoflurane 5% and maintained with air, oxygen, sevoflurane 3%, and fentanyl (total, 3 µg/kg). Neuromuscular monitoring was performed at the adductor pollicis muscle after induction of anesthesia but before the administration of rocuronium. Total dose of rocuronium during the surgery was 0.9 mg/kg. Neuromuscular block was reversed with 0.5 mg/kg sugammadex when one response was observed with post-tetanic count stimulation. Twitch responses after sugammadex administration showed a temporary decrease after its initial recovery. Maximum decreases in twitch responses were observed 17 min after initial dose of sugammadex. Twitch responses recovered to their control values after additional doses of 3.5 mg/kg sugammadex (4 mg/kg in total). Time from sugammadex administration to maximum decreases in twitch responses is earlier than has been reported in adults (20-70 min). It is demonstrated that following neuromuscular block reversal with insufficient dose of sugammadex, there is a possibility of the recurrence of residual paralysis within less than 20 min in pediatric patients.

Monitoring of neuromuscular blockade in one muscle group alone may not reflect recovery of total muscle function in patients with ocular myasthenia gravis.

PURPOSE: We report on two patients with ocular myasthenia gravis who received rocuronium, followed later by sugammadex to reverse neuromuscular blockade. Recovery was monitored simultaneously at the adductor pollicis muscle (APM) and the corrugator supercilii muscle (CSM). CLINICAL FEATURES: Two patients with ocular myasthenia gravis (case 1: 74 yr-old female, 54 kg; case 2: 71 yr-old male, 72 kg) were scheduled for surgery under general anesthesia. Neuromuscular blockade was induced with rocuronium 0.3 mg·kg(-1) after placing two separate monitors at the APM and the CSM, respectively. Additional doses of rocuronium 0.1-0.2 mg·kg(-1) were given to maintain neuromuscular blockade at fewer than two twitches at the APM during surgery. Train-of-four response at the CSM did not show recovery of the twitch after its initial disappearance. At the end of surgery, sugammadex was administered. Twitch height at the APM recovered to the control value in 12 min (case 1) and 13 min (case 2) after sugammadex administration; however, twitch height at the CSM took 26 min (case 1) and 14 min (case 2) to recover to the control value. CONCLUSION: After rocuronium-induced paralysis in both patients with ocular myasthenia, spontaneous recovery and sugammadex-assisted recovery were slower at the CSM than at the APM. In patients without the disorder, CSM recovery is faster than APM recovery. Thus, in ocular myasthenia gravis, neuromuscular recovery at the APM may not reflect recovery of all muscles.

[Characteristics and effectiveness of sugammadex].

Sugammadex was synthesized as a selective reversal agent for rocuronium, a steroidal non-depolarizing neuromuscular blocking (NMB) agent. Sugammadex exerts its effect by forming very tight water-soluble complexes at a 1 : 1 ratio with steroidal NMB agents. Because the reversal of NMB could not sufficiently be completed by anti-cholinesterase agents such as neostigmine, we often had to wait until their spontaneous recovery. Sugammadex altered the situation because of its rapid and potent antagonistic action. The rapid reversal can be explained by rapid redistribution of free rocuronium from the neuromuscular junction to the plasma. The reversal effects are not influenced by anesthetics. There is no interaction with cholinergic systems. Therefore, undesired side effects attendant with anti-cholinesterases are not seen. This article provides information on the characteristics and effectiveness of sugammadex.

[Evaluation of neuromuscular blockade using TOF-Watch SX in type 2 diabetes patients].

BACKGROUND: Differences in the supramaximal current (STIM) and sensitivity of the transducer (SENS) after calibration using mode "CAL2" of the neuromuscular accelermyography (TOF-Watch SX, MSD, Japan) between type 2 diabetic and non-diabetic patients were evaluated undergoing general anesthesia. METHODS: Thirty four elective surgical patients (20-69 years) were enrolled in this study. We evaluated STIM, SENS, onset time of rocuronium (onset time), time from onset to first T1 appearance (T1 appearance) and time from T1 appearance to T2 appearance (T1-T2 time) by using TOF stimulation between type 2 diabetic patients and non-diabetic patients, retrospectively. RESULTS: Thirteen diabetic patients (DM group) and twenty one non-diabetic patients (non-DM group) were included in this analysis. The values of SENS in DM group were significantly higher compared to non-DM patients (207 +/- 59 vs 113 +/- 44). However, STIM did not differ significantly between the two groups. Anesthesia in the 6 patients in DM group (SEV-DM group) and 14 patients in the non-DM group (SEV-non DM group) were maintained with sevoflurane. The other 14 patients were maintained with desflurane (DES-DM: n = 7 and DES-non DM: n = 7). A significant difference in the SENS values only was observed between the two SEV groups. On the other hand, the onset time, T1 appearance and T1-T2 time were significantly longer in DES-DM patients than those in the DES-non DM group. CONCLUSIONS: It is demonstrated that the values in the SENS and the recovery speed (T1-T2 time) under measuring the degree of neuromuscular blockade by TOF stimulation were significantly higher in diabetic patients compared to non-diabetic patients. The present study provides additional confirmation of low neuromuscular response under peripheral electrical stimulation using TOF-Watch SX in type 2 diabetes patients, and attention should be paid to the evaluation of neuromuscular block using TOF-Watch SX in diabetic patients.

Dexmedetomidine can stabilize hemodynamics and spare anesthetics before cardiopulmonary bypass.

PURPOSE: We previously confirmed the effectiveness of dexmedetomidine (DEX) for stabilizing hemodynamics as well as sparing anesthetics during anesthetic induction in patients undergoing cardiac surgery (Kunisawa et al. in J Clin Anesth 21:194-199, 1). In this study, we investigated whether these effects of DEX continue until the start of cardiopulmonary bypass (CPB). METHODS: Twenty-two patients with mild to moderate cardiovascular disease were randomized into two groups [DF2 group: DEX dose of 0.7 µg/kg/h after initial dose and effect-site concentration (ESC) of fentanyl of 2 ng/ml; PF4 group: saline and ESC of fentanyl of 4 ng/ml]. Propofol was administered for anesthetic induction and maintenance. Hemodynamics, cardiovascular drugs, ESC of propofol, and cardiovascular responses to skin incision (SI) and sternotomy (St) were measured or calculated. RESULTS: Blood pressure (BP) at the pre-/post-SI periods was higher in the DEX group (137 ± 17/140 ± 16 mmHg) than in the placebo group (85 ± 9/109 ± 24 mmHg). Percent increases in cardiovascular response to SI or St were lower in the DEX group than in the placebo group (for example, 1.9 ± 2.2 vs. 27.4 ± 19.9% in systolic BP due to SI). ESCs of propofol at SI and St in the DEX group were lower than those in the placebo group. CONCLUSIONS: DEX combined with 2 ng/ml fentanyl before CPB can suppress the decrease in blood pressure at the pre- and post-SI periods, can blunt the cardiovascular responses to SI and St, and can spare the required ESC of propofol despite fentanyl concentration, which was half of that in the placebo group.

[Administration of sugammadex to a patient with myasthenia gravis with fade of the train-of-four ratio].

A 50-year-old man (weight 87 kg, height 171 cm) with myasthenia gravis (MG) was scheduled for extended thymectomy under general anesthesia. His preanesthetic train-of-four ratio (T4/T1) was 59%. The first twitch of the train-of-four (T1) was 130% after calibration. We administered rocuronium 10 mg (0.11 mg x kg(-1)) for tracheal intubation. Maximal suppression was achieved in 50 seconds. During the operation, we did continuous infusion of rocuronium to maintain T1 at 10%. We discontinued rocuronium infusion before the end of surgery. In patients with MG, deep levels of neuromuscular block can be achieved with less rocuronium. We hypothesized that the requirement of sugammadex in a patient with MG is less than that in normal patients. Therefore, we administered 0.5 mg x kg(-1) of sugammadex. After 5 min, T4/T1 had reached 54%, but T1 had not reached the control value; therefore, we administered additional 1.5 m x kg(-1) of sugammadex. Subsequently, T1 reached 120%. Patients with MG with fade on T4/T1 require a full dose of sugammadex, identical to the dose administered to normal patients.