Reversal with sugammadex for rocuronium-induced deep neuromuscular block after pretreatment of magnesium sulfate in rabbits.

BACKGROUND: Magnesium sulfate (MgSO4) has been used in the treatment of pre-eclampsia, hypertension and arrhythmia. Magnesium enhances the neuromuscular block of rocuronium. This study has been conducted to evaluate the reversal efficacy of sugammadex from deep rocuronium-induced neuromuscular block (NMB) during consistent pretreatment of MgSO4 in rabbits. METHODS: Twenty-eight rabbits were randomly assigned to four groups, a control group or study groups (50% MgSO4 150-200 mg/kg and 25 mg/kg/h IV), and received rocuronium 0.6 mg/kg. When post-tetanic count 1-2 appeared, sugammadex 2, 4, and 8 mg/kg was administered in the 2-mg group, control and 4-mg group, and 8-mg group, respectively. The recovery course after reversal of sugammadex administration was evaluated in each group. RESULTS: The mean serum concentration of magnesium was maintained at more than 2 mmol/L in the study groups, and the total dose of MgSO4 was more than 590 mg. The reversal effect of sugammadex on rocuronium-induced NMB in pretreated MgSO4 was not different from that in the group without MgSO4. The recovery time to train-of-four ratio 0.9 after sugammadex administration in the 2-mg group was longer than in the other groups (P < 0.001); there were no other significant differences among the groups. CONCLUSIONS: The reversal of sugammadex from a deep rocuronium-induced NMB during large pretreatment of MgSO4 was not affected. However, we should consider that the reversal effect of sugammadex varied depending on the dose.

Relationship between first-twitch depression and train-of-four ratio during sugammadex reversal of rocuronium-induced neuromuscular blockade.

BACKGROUND: The primary outcome of sugammadex reversal for rocuronium-induced neuromuscular block (NMB) is a train-of-four ratio (TOFR) of 0.9, not first twitch (T1) height. We investigated whether the recovery of TOFR or T1 differs based on the reversal of NMB with neostigmine or sugammadex. METHODS: The acceleromyographic responses from 0.6 mg/kg of rocuronium were monitored supramaximally in 80 patients after induction of anesthesia. The TOFR and T1 height were recorded, and saved in a personal computer using TOF-Watch SX Monitor software in all patients. Patients were randomly assigned to 2 groups to receive either neostigmine 50 µg/kg with glycopyrrolate 10 µg/kg (neostigmine group, n = 40) or sugammadex 2.0 mg/kg (sugammadex group, n = 40). The primary objective was to determine the difference of recovery time between TOFR to 0.9 and T1 to 0.9 after sugammadex or neostigmine administration during moderate rocuronium-induced NMB. RESULTS: The recovery pattern of the TOFR 2 min after sugammadex administration was 1.0 or more, but that of T1 was less than 90% (T1 / control value) up to 6 min after drug was injected. The recovery pattern of TOFR and T1 was similar during the 20 min after reversal with neostigmine. CONCLUSIONS: If you have not performed the T1 monitoring, both TOFR and T1 should be considered to confirm suitable recovery during the 6 min after reversal with sugammadex during rocuronium-induced moderate NMB.

The influence of mild hypothermia on reversal of rocuronium-induced deep neuromuscular block with sugammadex.

BACKGROUND: Mild hypothermia may be frequently induced due to cool environments in the operating room. The study analyzed patient recovery time and response to sugammadex after a prolonged rocuronium-induced deep neuromuscular block (NMB) during mild hypothermia. METHODS: Sixty patients were randomly (1:1) allocated to the mild hypothermia and normothermia groups, defined as having core temperatures between 34.5-35°C and 36.5-37°C, respectively. Patients received 0.6 mg/kg of rocuronium, followed by 7-10 µg/kg/min to maintain a deep NMB [post-tetanic count (PTC) 1-2]. After surgery, the deep NMB was reversed with sugammadex 4.0 mg/kg. The primary end-point was the time until the train-of-four (TOF) ratio was 0.9. RESULTS: The appropriate neuromuscular function (TOF ratio ≥ 0.9) was restored after sugammadex was administered, even after hypothermia. The length of recovery in the hypothermia patients [mean (SD), 171.1 (62.1) seconds (s)] was significantly slower compared with the normothermia patients [124.9 (59.2) s] (p = 0.005). There were no adverse effects from sugammadex. CONCLUSIONS: Sugammadex safely and securely reversed deep rocuronium-induced NMB during mild hypothermia. An additional 46 s was required for recovery from a deep NMB in hypothermia patients. Based on the results, we think this prolonged recovery time is clinically acceptable. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01965067.

The dose effect of ephedrine on the onset time and intubating conditions after cisatracurium administration.

BACKGROUND: The aim of this randomized, double-blind, placebo-controlled study was to evaluate dose effects of ephedrine pretreatment on the onset time and intubating conditions after cisatracurium administration. METHODS: A total of 140 adult patients were randomized into 4 groups to receive either 30 µg/kg ephedrine (Group 30, n = 35), 70 µg/kg ephedrine (Group 70, n = 35), 110 µg/kg ephedrine (Group 110, n = 35), 3 ml normal saline (Group C, n = 35) as pretreatment given 30 s before anesthetic induction. Neuromuscular block was achieved with 0.15 mg/kg cisatracurium, evaluated accelomyographically with train-of-four stimulation. An anesthesiologist blinded to patient grouping assessed the intubating conditions 1.5 min after cisatracurium administration. RESULTS: An onset time of 70 s was obtained in the ephedrine groups (Group 30: 155.4 ± 44.7 s, Group 70: 152.6 ± 40.3 s, Group 110: 151.2 ± 51.6 s) compared to Group C (224.6 ± 56.9 s) after 0.15 mg/kg of cisatracurium (P < 0.001). Ephedrine doses of either 70 or 110 µg/kg for pretreatment significantly improved intubating conditions (P < 0.05). Systolic and diastolic blood pressure and heart rate at 1 min after tracheal intubation were significantly increased than other times in all groups (P < 0.001), with no differences among the groups. However, 5 patients in Group 110 experienced marked hypertension (systolic/diastolic blood pressure: > 200/100 mmHg) 1 min after tracheal intubation with no patients in other groups. CONCLUSIONS: We conclude that pre-treatment with ephedrine 70 µg/kg improved intubating conditions 1.5 min after cisatracurium administration and facilitated the onset of neuromuscular block (70 s) without adverse hemodynamic effects.

The use of 3 sugammadex out of 5 reversal of during recovery of rocuronium-induced neuromuscular blockade in a patient with post-tonsillectomy hemorrhage: a case report.

Post-tonsillectomy hemorrhage (PTH) is the most frequent complication of tonsillectomy, and occasionally results in a lethal outcome. A 21-year-old man (height 180 cm, weight 95 kg) was scheduled for a bilateral tonsillectomy and uvulopalatopharyngoplasty for treatment of obstructive sleep apnea. He required 5 rounds of general anesthesia due to recurrent PTH. The anesthesiologist used sugammadex a total of 3 times to achieve the successful reversal of the deep neuromuscular blockade (NMB) induced by rocuronium. After sugammadex 2 mg/kg was administered, the NMB was reversed in 2 minutes each time. Re-administration of rocuronium within a short time interval after sugammadex may result in unpredictable effects of neuromuscular blocking agents. Sugammadex made it possible to perform a rapid, complete reverse when the residual block was maintained by an incomplete reversal of anticholinesterase.

Optimal precurarizing dose of rocuronium to decrease fasciculation and myalgia following succinylcholine administration.

BACKGROUND: Succinylcholine commonly produces frequent adverse effects, including muscle fasciculation and myalgia. The current study identified the optimal dose of rocuronium to prevent succinylcholine-induced fasciculation and myalgia and evaluated the influence of rocuronium on the speed of onset produced by succinylcholine. METHODS: This randomized, double-blinded study was conducted in 100 patients randomly allocated into five groups of 20 patients each. Patients were randomized to receive 0.02, 0.03, 0.04, 0.05 and 0.06 mg/kg rocuronium as a precurarizing dose. Neuromuscular monitoring after each precurarizing dose was recorded from the adductor pollicis muscle using acceleromyography with train-of-four stimulation of the ulnar nerve. All patients received succinylcholine 1.5 mg/kg at 2 minutes after the precurarization, and were assessed the incidence and severity of fasciculations, while myalgia was assessed at 24 hours after surgery. RESULTS: The incidence and severity of visible muscle fasciculation was significantly less with increasing the amount of precurarizing dose of rocuronium (P < 0.001). Those of myalgia tend to decrease according to increasing the amount of precurarizing dose of rocuronium, but there was no significance (P = 0.072). The onset time of succinylcholine was significantly longer with increasing the amount of precurarizing dose of rocuronium (P < 0.001). CONCLUSIONS: Precurarization with 0.04 mg/kg rocuronium was the optimal dose considering the reduction in the incidence and severity of fasciculation and myalgia with acceptable onset time, and the safe and effective precurarization.

Optimal positive end-expiratory pressure during robot-assisted laparoscopic radical prostatectomy.

BACKGROUND: Increased intra-abdominal pressure during laparoscopic surgery causes cephalad displacement of the diaphragm, resulting in the formation of atelectasis, which can be overcome by positive end-expiratory pressure (PEEP). The aim of this prospective study was to investigate the level of optimal PEEP to maintain adequate arterial oxygenation and hemodynamics during robot-assisted laparoscopic radical prostatectomy (RLRP). METHODS: One hundred patients undergoing RLRP were randomly allocated to one of five groups (n = 20) (0, 3, 5, 7 and 10 cmH2O of PEEP). Hemodynamic variables and respiratory parameters were measured at baseline with the patient in the supine position; at 30 min, 1, 2, 3 and 4 h during CO2 insufflation with the patient in the post-Trendelenburg position; and after deflation in the supine position with increasing PEEP. RESULTS: The PaO2 levels and alveolar-arterial difference in oxygen tension (AaDO2) were improved in patients with PEEPs compared with patients in whom PEEP was not used. The application of PEEP (10 cmH2O) resulted in higher PaO2 levels compared to those with lower PEEP levels, but excessive peak airway pressure (PAP) was sometimes observed. The application of a PEEP of 7 cmH2O resulted in similar PaO2 levels without causing excessive PAP. There was a significant difference in central venous pressure between the groups, but there were no significant differences in heart rate, mean arterial pressure or minute ventilation between the groups. CONCLUSIONS: A PEEP of 7 cmH2O is associated with the greater improvement of PaO2 and AaDO2 without causing excessive PAP during RLRP.

The effect of hand dominance on neuromuscular monitoring at the adductor pollicis muscle.

BACKGROUND: Neuromuscular blockade of the adductor pollicis muscle may be influenced by hand dominance resulting in conflicting results of several studies. The current study examined whether hand dominance could influence the measurements of neuromuscular blockade with acceleromyography at the adductor pollicis. METHODS: The acceleromyographic responses from 0.6 mg/kg of rocuronium were monitored supramaximally in both hands in 31 patients after induction of anesthesia. Onset, maximum effect, and offset of rocuronium were measured and compared in both hands. The train-of-four (TOF) ratios to 0.9 were recorded in all patients. RESULTS: In total, 27 patients were right-handed and 4 patients were left-handed. The mean supramaximal threshold or initial TOF ratio was not different between dominant and nondominant hands. No statistically significant differences were found between 716 paired TOF ratios in both hands. A correlation was seen between the dominant and nondominant hand (Nondominant = 0.931·Dominant + 1.714, R = 0.929). The analysis by the Bland-Altman plot showed an excellent agreement with a bias of 1.6% and limits of agreement of -21.2 to 24.5%. CONCLUSIONS: Dominant and nondominant hands can be used interchangeably for neuromuscular monitoring at the adductor pollicis.

Sugammadex versus neostigmine reversal of moderate rocuronium-induced neuromuscular blockade in Korean patients.

BACKGROUND: Rapid and complete reversal of neuromuscular blockade (NMB) is desirable at the end of surgery. Sugammadex reverses rocuronium-induced NMB by encapsulation. It is well tolerated in Caucasian patients, providing rapid reversal of moderate (reappearance of T2) rocuronium-induced NMB. We investigated the efficacy and safety of sugammadex versus neostigmine in Korean patients. METHODS: This randomized, safety assessor-blinded trial (NCT01050543) included Korean patients undergoing general anesthesia. Rocuronium 0.6 mg/kg was given prior to intubation with maintenance doses of 0.1-0.2 mg/kg as required. Patients received sugammadex 2.0 mg/kg or neostigmine 50 µg/kg with glycopyrrolate 10 µg/kg to reverse the NMB at the reappearance of T2, after the last rocuronium dose. The primary efficacy endpoint was the time from sugammadex or neostigmine administration to recovery of the train-of-four (TOF) ratio to 0.9. The safety of these medications was also assessed. RESULTS: Of 128 randomized patients, 118 had evaluable data (n = 59 in each group). The geometric mean (95% confidence interval) time to recovery of the TOF ratio to 0.9 was 1.8 (1.6, 2.0) minutes in the sugammadex group and 14.8 (12.4, 17.6) minutes in the neostigmine group (P < 0.0001). Sugammadex was generally well tolerated, with no evidence of residual or recurrence of NMB; four patients in the neostigmine group reported adverse events possibly indicative of inadequate NMB reversal. CONCLUSIONS: Sugammadex was well tolerated and provided rapid reversal of moderate rocuronium-induced NMB in Korean patients, with a recovery time 8.1 times faster than neostigmine. These results are consistent with those reported for Caucasian patients.

Antiemetic efficacy of capsicum plaster on acupuncture points in patients undergoing thyroid operation.

BACKGROUND: Postoperative nausea and vomiting (PONV) occurs in up to 63-84% of patients after thyroid surgery. This study aims to assess the effects of using a capsicum plaster to reduce PONV after thyroid surgery at either the Chinese acupuncture point (acupoint) Pericardium 6 (P6) or Korean hand acupuncture point K-D2. METHODS: One-hundred eighty-four patients who underwent thyroid surgery were randomized in four groups (n = 46 each): control group = inactive tape at P6 acupoints and on both shoulders as a nonacupoint; P6 group = capsicum plaster at P6 points and inactive tape on both shoulders; K-D2 group = capsicum plaster at K-D2 acupoints and inactive tape on both shoulders; Sham group = capsicum plaster on both shoulders and inactive tape at P6 acupoints. The capsicum plaster was applied before the induction of anesthesia and removed at 8 hr after surgery. RESULTS: The incidence and severity of nausea and vomiting and the need for rescue antiemetics were decreased in the patients in the P6 and K-D2 groups compared to the patients in the control and sham groups (P < 0.001). The patients in the P6 and K-D2 groups also reported that they were more satisfied (P < 0.05). CONCLUSIONS: We conclude that the capsicum plaster at the P6 and K-D2 acupoint was a promising antiemetic method for the patients undergoing thyroid surgery.

A comparison of the accuracy of ulnar versus median nerve stimulation for neuromuscular monitoring.

BACKGROUND: Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve. METHODS: In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites. RESULTS: None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (± 31%) and 26% (± 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve. CONCLUSIONS: The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.

Rocuronium-induced neuromuscular block after long pretreatment of clonidine in rabbits.

BACKGROUND: Clonidine, an α-2 adrenergic agonist, is used in the perioperative period and in intensive care for the management of hypertension. The in vivo and in vitro effects of clonidine on the actions of nondepolarizing neuromuscular blocking drugs are conflicting. We evaluated the potency and time course of rocuronium-induced neuromuscular block after prolonged pretreatment with clonidine in rabbits. METHODS: Sixty rabbits were randomly assigned to three groups; control (C) group: normal saline 0.1 ml/kg daily subcutaneous for 6 weeks; S3 group: clonidine 4 µg/kg daily subcutaneous for 3 weeks; S6 group: clonidine 4 µg/kg daily subcutaneous for 6 weeks. The dose-response relations of rocuronium were tested in 30 rabbits (10 from each of the three groups) during ketamine-thiopental anesthesia, while the time course of rocuronium 0.6 mg/kg was examined in 10 rabbits each from the three groups. RESULTS: There was no difference in mean arterial pressure and pulse rate among the experimental groups. The calculated ED(50) for rocuronium decreased significantly from 64.1 µg/kg (C group) to 50.3 µg/kg (S3 group) and 47.8µg/kg (S6 group) (P < 0.001). There was no difference in the onset and the recovery times after rocuronium. CONCLUSIONS: Rocuronium after pretreatment with clonidine for three or six weeks may have an increased effect, but no difference in the duration of action compared with control group.

Anesthetic consideration for patients with severe tracheal obstruction caused by thyroid cancer -A report of 2 cases-.

To achieve safe airway management, it is essential first to predict whether there will be difficulties in intubating or ventilating the patient's airway. An enlarged thyroid mass can produce a tracheal obstruction by compression or intraluminal invasion or both. We report two patients with thyroid cancer that obstructed the trachea by compression or invasion. There was no difficulty in endotracheal intubation of the patients with marked thyroid enlargement or in securing passage of the endotracheal tube through the compressed or narrowed portion of the trachea.

The hemodynamic effects of a reversed Trendelenburg in elderly patients with increased cardiac risk during laparoscopic cholecystectomy.

BACKGROUND: We studied the hemodynamic changes induced by pneumoperitoneum and a reversed Trendelenburg in elderly patients with increased cardiac risk (ASA class III; n = 30; age 70.8 +/- 4.9 years, mean +/- SD) and compared the results with elderly patients at normal risk (ASA class II; n = 30; age 69.2 +/- 4.1 years) during laparoscopic cholecystectomy. METHODS: The transesophageal Doppler monitor was performed after induction of general anesthesia (pre-incision), after onset of pneumoperitoneum (insufflation), after head-up (20degrees) and a left lateral tilt (15degrees) (reversed Trendelenburg) and after deflation and horizontal position (desufflation). Mean arterial pressure (MAP), heart rate, cardiac index (CI) and systemic vascular resistance (SVR) were measured, respectively. RESULTS: Induction of pneumoperitoneum and head-up tilt in patients with cardiac risk resulted significantly in a decrease in CI and an increase in SVR compared with patients with normal risk (P < 0.05), and that remained until deflation, but no interval changes in MAP and heart rate. The CI, MAP and heart rate decreased and SVR increased significantly in patients with cardiac risk compared with patients with normal risk before incision (P < 0.05). No complications occurred. The results indicate that pneumoperitoneum and a reversed Trendelenburg are associated with significant but relatively benign hemodynamic changes. CONCLUSIONS: Anesthesia for laparoscopic cholecystectomy in elderly patients with increased cardiac risk should be performed with an adequate hemodynamic monitoring.

Time course of neuromuscular effects of rocuronium during desflurane anesthesia in patients with or without renal failure.

BACKGROUND: This study aimed to investigate the neuromuscular effects of 0.6 mg/kg rocuronium under desflurane anesthesia in patients with and without renal failure. METHODS: The neuromuscular effects of rocuronium 0.6 mg/kg under desflurane anesthesia were investigated in 20 patients with renal failure undergoing renal transplantation surgery and in 20 patients with normal renal function. Neuromuscular transmission was monitored using acceleromyography with single stimuli at 0.1 Hz. The onset and 25%, 75%, and 95% twitch recovery times, the recovery of the train-of-four ratio to 70% (TOF70), and the recovery index (25-75%) were recorded. RESULTS: Block onset was similar in the groups. The 25%, 75% and 95% twitch recovery times, the TOF70 time, and the recovery index were found to be prolonged in patients with renal failure compared to those with normal renal function (e.g. TOF70: 123.1 +/- 49.1 vs. 68.7 +/- 15.5 min) (P<0.001). A very strong association between the time to TOF70 and the diagnostic duration of renal failure was found (R2 = 0.79, P<0.001). CONCLUSIONS: The duration of action of a bolus dose of 0.6 mg/kg rocuronium under desflurane anesthesia was increased significantly in patients with end-stage renal failure compared to that of healthy controls and was prolonged according to the duration of renal failure.

Ephedrine reduces the pain from propofol injection.

UNLABELLED: One hundred seventy-six patients (ASA physical status I or II) presenting for elective surgery were randomly allocated into six study groups to compare the incidence of propofol-induced pain after pretreatment with different doses of ephedrine as compared with lidocaine. Patients in Group P (n = 30) received saline placebo; patients in Group L (n = 30) received 2% lidocaine 40 mg; patients received ephedrine 30 microg/kg (Group E30, n = 28), 70 microg/kg (Group E70, n = 30), 110 microg/kg (Group E110, n = 30), and 150 microg/kg (Group E150, n = 28), respectively, followed 30 s later by propofol 2.5 mg/kg. A blinded anesthesiologist asked the patient to evaluate the pain score (verbal rating scale and face pain scale). The incidence and intensity of pain was less in the lidocaine and ephedrine groups than in the placebo group (P < 0.01). Before tracheal intubation, the arterial blood pressure was decreased in the P and L groups, and after intubation, hemodynamics were increased in the E110 and E150 groups, respectively (P < 0.05). We concluded that pretreatment with a small dose of ephedrine (30 and 70 microg/kg) reduced the incidence and intensity of propofol-induced pain with a lesser decrease in arterial blood pressure than from propofol alone in lidocaine pretreatment. IMPLICATIONS: Propofol is a widely used IV anesthetic for the induction of anesthesia, but it often causes local pain when administered into peripheral veins. A small dose of ephedrine reduces the incidence and intensity of the pain without significant adverse hemodynamic effects during induction.