The expected advantage of administering prophylactic antibiotics using target- concentration controlled infusion: Development of a new pharmacokinetic model of cefazolin.

The aim of this study was to explore the utility of target-concentration controlled infusion (TCI) as a prophylactic antibiotic administration method based on the results of a population pharmacokinetic model of cefazolin. In patients undergoing elective gastric surgery, 2 g of cefazolin was dissolved in 50 mL of saline and administered for 10 min prior to skin incision. Arterial blood samples were obtained at preset intervals to measure the total and free plasma concentrations of cefazolin. Population pharmacokinetic analysis was performed using non-linear mixed-effects modelling. To evaluate the effectiveness of the TCI method, stochastic simulation was performed based on the model construction results. In total, 360 total and 360 free plasma concentration measurements from 40 patients were used to characterise the pharmacokinetics of cefazolin. The changes in the total concentration of cefazolin over time were well-explained by the three-compartment mammillary model. Fat-free mass and estimated glomerular filtration rate were significant covariates. The probability of target attainment (PTA) to reach the target 100% fraction of time that the free plasma concentration of cefazolin was maintained above its minimal inhibitory concentration (fT > MIC) at MIC of 4 mg/L was also notably higher in the TCI method (90.7%) than in the standard method (17.0%). When cefazolin is administered by the TCI method, patient-tailored antibiotic dosing may be possible. The potential benefits of administering prophylactic antibiotics by the TCI method were observed. Further research is warranted to confirm the effectiveness of the TCI method.

Reversal of residual neuromuscular block with neostigmine or sugammadex and postoperative pulmonary complications: a prospective, randomised, double-blind trial in high-risk older patients.

BACKGROUND: Residual neuromuscular block is associated with an increased risk of postoperative pulmonary complications in retrospective studies. The aim of our study was to investigate prospectively the incidence of postoperative pulmonary complications after reversal with either sugammadex (SUG) or neostigmine (NEO) in high-risk older patients. METHODS: We randomly allocated 180 older patients with significant morbidity (ASA physical status 3) ≥75 yr old to reversal of rocuronium with either SUG or NEO. Adverse events in the recovery room and pulmonary complications (defined by a 5-point [0-4; 0=best to 4=worst] outcome score) on postoperative Days 1, 3, and 7 were compared between groups. RESULTS: Data from 168 patients aged 80 (4) yr were analysed; SUG vs NEO resulted in a reduced probability (0.052 vs 0.122) of increased pulmonary outcome score (impaired outcome) on postoperative Day 7, but not on Days 1 and 3. More patients in the NEO group were diagnosed with radiographically confirmed pneumonia (9.6% vs 2.4%; P=0.046). The NEO group showed a non-significant trend towards longer hospital length of stay across all individual centres (combined 9 vs 7.5 days), with a significant difference in Malaysia (6 vs 4 days; P=0.011). CONCLUSIONS: Reversal of rocuronium neuromuscular block with SUG resulted in a small, but possibly clinically relevant improvement in pulmonary outcome in a select cohort of high-risk older patients. CLINICAL TRIAL REGISTRATION: ACTRN12614000108617.

Effects of hyperthermia on the effective concentration of rocuronium and sugammadex-mediated reversal in isolated phrenic nerve hemidiaphragm preparations of rats.

BACKGROUND: Hyperthermia is relatively rare during general anesthesia; however, a few studies have been conducted on hyperthermia and the neuromuscular blockade (NMB) induced by rocuronium, and the reversal of NMB by sugammadex. We investigated the effect of hyperthermia status on the NMB induced by rocuronium, and its reversal by sugammadex, in isolated phrenic nerve hemidiaphragm (PNHD) preparations of the rat. METHODS: Thirty-three male Sprague-Dawley rat PNHD preparations were randomly assigned to three groups at different temperatures (36 °C, 38 °C, and 40 °C; each group, n = 11, in Krebs solution). The train-of-four (TOF) and twitch height responses were checked mechanomyographically. The PNHD were treated with progressively increasing doses of rocuronium and three effective concentrations (ECs), EC50, EC90, and EC95, of rocuronium were analyzed in each group via nonlinear regression analysis. Then, sugammadex was administered in doses equimolar to rocuronium. Thereafter, the T1 height (%), TOFR (%) and the duration index were measured. RESULTS: The EC of rocuronium (EC50, EC90, and EC95) decreased significantly in accordance with increasing temperature. The groups at 36 °C and 40 °C showed clear differences in all areas (all P < 0.001). Moreover, the T1 height (%) and the duration index upon sugammadex administration showed faster recovery results in the36 °C than the 38 °C and 40 °C groups. CONCLUSION: A rise of temperature from 38 °C to 40 °C in rat PNHD preparations proportionally enhanced the NMB induced by rocuronium. In addition, equimolar doses of sugammadex to the administered rocuronium showed a slower recovery time as the temperature rises.

Remifentanil does not inhibit sugammadex reversal after rocuronium-induced neuromuscular block in the isolated hemidiaphragm of the rat: an ex vivo study.

PURPOSE: Sugammadex is used to reverse neuromuscular block induced by rocuronium or vecuronium by forming a stable complex. If the binding capacity of any substance to sugammadex is large enough, this molecule will displace rocuronium or vecuronium from the complex. For drugs used in anesthesia, the binding affinity of remifentanil for sugammadex was highest. The aim of the current study was to investigate the decrease in the reversal of neuromuscular blockade with sugammadex by complex formation between remifentanil and sugammadex in the model using isolated hemidiaphragm of the rat. METHODS: Phrenic nerve-hemidiaphragms from 34 male Sprague-Dawley rats were allocated randomly to four groups: 0 or 100 ng/ml remifentanil with equimolar amounts of sugammadex and 0 or 100 ng/ml remifentanil with three-quarter dose of sugammadex. Muscle contraction responses were recorded during the stimulation of the phrenic nerve by train-of-four (TOF) stimulation. Rocuronium was added to the organ bath with or without 100 ng/ml remifentanil until the first height response (T1) of TOF disappeared completely. Then, equimolar amounts or three-quarter dose of sugammadex was added. RESULTS: Remifentanil has no significant effects on the concentration-response curves of rocuronium. No significant differences were observed in the recoveries of T1 and TOF ratio with time after administration of equimolar amounts or three-quarter dose of sugammadex regardless of the presence of 100 ng/ml remifentanil. CONCLUSION: Clinical concentration of remifentanil does not inhibit sugammadex reversal after rocuronium-induced neuromuscular block. Sugammadex can be used safely without worrying about the interaction with remifentanil.

Effects of neuromuscular presynaptic muscarinic M1 receptor blockade on rocuronium-induced neuromuscular blockade in immobilized tibialis anterior muscles.

This in vivo study tested the hypothesis that the modulation of acetylcholine (ACh) release by the M1 muscarinic receptor (mAChR) in the neuromuscular junction of disused muscles may affect the tensions of the muscles during the neuromuscular monitoring of a rocuronium-induced neuromuscular block and compared the results with those obtained from normal muscles. A total of 20 C57BL/6 (wild-type) and 10 α7 knock out (α7KO) mice were used in this experiment. As a pre-experimental procedure, knee and ankle joints of right hind limbs were fixed by needle pinning at the 90° flexed position. After 2 weeks, the main experiment was performed. Both tendons of the tibialis anterior (TA) muscles were obtained, and the muscle tensions were recorded while the dose-responses of rocuronium were measured three times in the same mouse by the serial administration of pirenzepine (0, 0.001 and 0.01 µg/g). Weight losses were observed after 2 weeks of immobilization in both groups, and a decrease in the mass of TA muscles at the immobilized side was observed compared to those of the contralateral nonimmobilized side. Tension depression of the TA muscles at immobilized side of the α7KO group was faster than those of the wild-type group, but these differences decreased after the administration of pirenzepine. The tension depressions were similar regardless of the pirenzepine doses at the same side in the group. Tension depression may become more rapid in the α7 AChR-expressed disused muscles by the decreased release of ACh release upon neuronal firing by the blockade of facilitatory M1 mAChR.

Dexamethasone concentration affecting rocuronium-induced neuromuscular blockade and sugammadex reversal in a rat phrenic nerve-hemidiaphragm model: An ex vivo study.

BACKGROUND: The concentration range of dexamethasone that inhibits neuromuscular blockade (NMB) and sugammadex reversal remains unclear. OBJECTIVE: To evaluate the effects of dexamethasone on rocuronium-induced NMB and sugammadex reversal. DESIGN: Ex vivo study. SETTING: Asan Institute for Life Sciences, Asan Medical Center, Korea, from July 2015 to November 2015. ANIMALS: One hundred sixty male Sprague-Dawley rats. INTERVENTIONS: We assessed the effect of four concentrations of dexamethasone [0, 0.5, 5 (clinical concentrations) and 50 µg ml (experimental concentration)] on partial NMB on 40 phrenic nerve-hemidiaphragm preparations (n=10 per concentration). Once the first twitch of train-of-four (TOF) had been depressed by 50% with rocuronium, dexamethasone was administered. To assess the effect of dexamethasone on sugammadex reversal, 120 phrenic nerve-hemidiaphragm preparations were used in three subexperiments (n=40 per experiment), using three administration regimens of rocuronium-equimolar sugammadex: a single dose, a split-dose (split and ) and a reduced split-dose (split and ). After complete NMB was achieved, dexamethasone and sugammadex were administered. MAIN OUTCOME MEASURES: The change in the first twitch height, the recovery time to a TOF ratio at least 0.9, and the TOF ratio at 30 min were evaluated. RESULTS: There were no significant differences in the first twitch height among groups (P = 0.532). With a single dose of sugammadex, dexamethasone did not affect the recovery time to a TOF ratio at least 0.9 (P = 0.070). After using a split-dose of sugammadex, the recovery time to a TOF ratio at least 0.9 was delayed only at a concentration of 50 µg ml of dexamethasone. With a reduced split-dose of sugammadex, the TOF ratio at 30 min was lowered only by a concentration of 50 µg ml of dexamethasone (P < 0.010). CONCLUSION: Acute bolus administration of dexamethasone at clinical concentrations had no effect on NMB or on sugammadex reversal.

Effects of magnesium chloride on rocuronium-induced neuromuscular blockade and sugammadex reversal in an isolated rat phrenic nerve-hemidiaphragm preparation: An in-vitro study.

BACKGROUND: Magnesium potentiates the effects of nondepolarising muscle relaxants. However, few studies have used magnesium chloride (MgCl2). Sugammadex reverses neuromuscular block by steroidal nondepolarising muscle relaxants. OBJECTIVES: To assess the effects of MgCl2 on rocuronium-induced neuromuscular blockade and its reversal by sugammadex. DESIGN: In-vitro experimental study. SETTING: Animal laboratory, Asan Medical Center, Seoul, South Korea, from 20 March 2016 to 3 April 2016. ANIMALS: Forty male Sprague Dawley rats. INTERVENTION: Left phrenic nerve-hemidiaphragms from 40 Sprague Dawley rats were allocated randomly to four groups (1, 2, 3 and 4 mmol l MgCl2 group, n = 10 each). Rocuronium was administered cumulatively until the first twitch of train-of-four (TOF) disappeared completely. Then, equimolar sugammadex was administered. MAIN OUTCOME MEASURES: The effective concentration (EC) of rocuronium was obtained in each group. After administering sugammadex, recovery of the first twitch height and the TOF ratio were measured for 30 min. RESULTS: EC50, EC90 and EC95 significantly decreased as the concentration of MgCl2 increased (all P ≤ 0.001), except the comparison between the 3 and 4 mmol l MgCl2 groups. After administration of sugammadex, the maximal TOF ratio (%) was lower in the 4 mmol l MgCl2 group than the 1 mmol l MgCl2 group [median 91.7 interquartile range (83.4 to 95.8) vs. 98.3 interquartile range (92.2 to 103.4), P = 0.049]. The mean time (s) from sugammadex injection to achieving maximal first twitch was significantly prolonged in the 4 mmol l MgCl2 group vs. the 1 mmol l MgCl2 and 2 mmol l MgCl2 groups [1483.9 (±â€Š237.0) vs. 1039.0 (±â€Š351.8) and 926.0 (±â€Š278.1), P = 0.022 and 0.002, respectively]. CONCLUSION: Increases in MgCl2 concentration reduce the ECs of rocuronium. In addition, administering sugammadex equimolar to the administered rocuronium shows limited efficacy as MgCl2 concentration is increased. TRIAL REGISTRATION: The in-vitro study was not registered in a database.

Effects of presynaptic muscarinic cholinoreceptor blockade on neuromuscular transmission as assessed by the train-of-four and the tetanic fade response to rocuronium.

This study investigated the effect of muscarinic M1 and M2 receptor antagonists on the rocuronium-induced train of four (TOF) fade and tetanic fade, respectively. Ex-vivo phrenic nerves and diaphragms were obtained from adult Sprague-Dawley rats and stabilized in Krebs buffer; the nerve-stimulated muscle TOF fade was observed at 20 s intervals. For the TOF study, phrenic nerves and diaphragms were incubated with pirenzepine (an M1 blocker) at concentrations of 0 nmol L-1 (control), 10 nmol L-1 (PZP10), or 100 nmol L-1 (PZP100). Rocuronium was then administered incrementally until the first twitch tension had depressed by >95% during TOF stimulation. The mean TOF ratios were compared when the first twitch tensions were depressed by 40%-50%. For the tetanic fade study, 50 Hz/5 s tetani was applied initially, 30 min after the administration of a loading dose of rocuronium and methoctramine (an M2 receptor blocker, loaded at 0 µmol L-1 [control], 1 µmol L-1 [MET1], or 10 µmol L-1 [MET10]). The EC95 of rocuronium was significantly lower in the PZP10 group than in the control group. In the PZP10 group, the TOF ratios at 50% and first twitch tension depression were significantly lower than those in the control group (P=.02). During tetanic stimulation, the tetanic fade was significantly enhanced in the MET10 group compared to the other groups. This study shows that antagonists of muscarinic M1 and M2 receptors affect the rocuronium-induced neuromuscular block as demonstrated by the reduced EC95 and TOF ratios (M1 antagonist, pirenzepine) or the enhanced 50-Hz tetanic fade (M2 antagonist, methoctramine).

The neuromuscular effects of rocuronium under sevoflurane-remifentanil or propofol-remifentanil anesthesia: a randomized clinical comparative study in an Asian population.

BACKGROUND: We conducted a prospective, randomized, multicenter study to evaluate the differences in the blocking effect of different doses of rocuronium between sevoflurane- or propofol-remifentanil anesthesia in an Asian population. METHODS: A total of 368 ASA I-II patients was enrolled. Anesthesia was induced with 2.0 mg/kg propofol and 0.1 µg/kg/min remifentanil (TIVA) or 5.0 vol.% sevoflurane with 0.1 µg/kg/min remifentanil (SEVO). Tracheal intubation was facilitated at 180 s after the administration of rocuronium at 0.3, 0.6, or 0.9 mg/kg and then intubation condition was evaluated. The time to maximum block and recovery profile were monitored by TOF stimulation of the ulnar nerve and by recording the adductor pollicis response using acceleromyography. RESULTS: The numbers of patients with clinically acceptable intubation conditions were 41, 82, and 97 % (TIVA) and 34, 85, and 90 % (SEVO) at each dose of rocuronium, respectively. There were no significant differences in the time to maximum block between groups at each rocuronium dose. There were significant differences in the recovery to a train-of-four ratio of 90 % between the groups: 42.7 (19.5), 74.8 (29.9), and 118.4 (35.1) min (TIVA) and 66.5 (39.3), 110.2 (43.5), and 144.4 (57.5) min (SEVO) at 0.3, 0.6, and 0.9 mg/kg, respectively (P < 0.001). CONCLUSIONS: There are no significant differences in intubation conditions between propofol-remifentanil and sevoflurane-remifentanil anesthesia at the same dose of rocuronium. The type of anesthetic does not significantly influence the time to maximum block by rocuronium. Rocuronium at a dose of 0.9 mg/kg should be used for better intubation conditions with both anesthesia regimens in an Asian population. TRIAL REGISTRATION: UMIN-CTR Clinical Trial ( http://www.umin.ac.jp/ctr/index.htm ; UMIN#000007289 ; date of registration 14(th) February 2012).

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.

Airway leakage due to malpositioning of esophageal temperature probe during robot-assisted radical prostatectomy: a case report.

Measuring patients' core body temperature during surgery is essential and commonly performed with an esophageal temperature probe. The probe must be placed in the lower third of the esophagus for accurate measurement. In this case report, we describe our experience of discovering an inadvertently malpositioned esophageal temperature probe in the right inferior lobar bronchus, which led to ventilation-related problems in a patient undergoing prostate surgery.

Oral administration of aprepitant to prevent postoperative nausea in highly susceptible patients after gynecological laparoscopy.

PURPOSE: The use of opioids following surgery is associated with a high incidence of postoperative nausea and vomiting (PONV). We conducted a prospective, randomized, double-blind, placebo-controlled study to investigate the effect of orally administered aprepitant, a neurokinin-1 receptor antagonist, for reducing PONV in patients with fentanyl-based, patient-controlled analgesia (PCA) given intravenously after gynecological laparoscopy. METHODS: One hundred and twenty female patients (ages 21-60) undergoing laparoscopic hysterectomy were randomly allocated to receive 80 mg (A80 group, n = 40) or 125 mg aprepitant (A125 group, n = 40) or placebo (control group, n = 40) orally 2 h before anesthesia induction. Anesthesia was maintained with isoflurane and remifentanil, and PCA IV using fentanyl and ketorolac were provided for 48 h after surgery. Incidences of nausea, vomiting/retching, and use of rescue antiemetics were recorded at 2, 24, and 48 h after surgery. Complete response was defined as no PONV and no need for rescue treatment. RESULTS: The incidence of complete response was significantly lower in the A80 and A125 groups than in controls, 56 % and 63 %, vs. 28 %, respectively, P = 0.007 and P = 0.003, respectively, during the first 48 h, and 65 % and 65 % vs. 38 %, respectively, both P = 0.025, during the first 2 h. However, there were no statistically significant differences between A80 and A125 groups in the incidences of complete response and PONV during the study period. CONCLUSIONS: Aprepitant 80 mg orally was effective in lowering the incidence of PONV in the first 48 h after anesthesia in patients receiving fentanyl-based PCA after gynecological laparoscopy.

Current clinical application of dantrolene sodium.

Dantrolene sodium (DS) was first introduced as an oral antispasmodic drug. However, in 1975, DS was demonstrated to be effective for managing malignant hyperthermia (MH) and was adopted as the primary therapeutic drug after intravenous administration. However, it is difficult to administer DS intravenously to manage MH. MH is life-threatening, pharmacogenomically related, and induced by depolarizing neuromuscular blocking agents or inhalational anesthetics. All anesthesiologists should know the pharmacology of DS. DS suppresses Ca2+ release from ryanodine receptors (RyRs). RyRs are expressed in various tissues, although their distribution differs among subtypes. The anatomical and physiological functions of RyRs have also been demonstrated as effective therapeutic drugs for cardiac arrhythmias, Alzheimer's disease, and other RyR-related diseases. Recently, a new formulation was introduced that enhanced the hydrophilicity of the lipophilic DS. The authors summarize the pharmacological properties of DS and comment on its indications, contraindications, adverse effects, and interactions with other drugs by reviewing reference articles.

Chronic exposure to dexamethasone may not affect sugammadex reversal of rocuronium-induced neuromuscular blockade: an in vivo study on rats.

BACKGROUND: Chronic glucocorticoid exposure is associated with resistance to nondepolarizing neuromuscular blocking agents. Therefore, we hypothesized that sugammadex-induced recovery would occur more rapidly in subjects exposed to chronic dexamethasone compared to those who were not exposed. This study evaluated the sugammadex-induced recovery profile after neuromuscular blockade (NMB) in rats exposed to chronic dexamethasone. METHODS: Sprague-Dawley rats were allocated to three groups (dexamethasone, control, and pair-fed group) for the in vivo study. The mice received daily intraperitoneal dexamethasone injections (500 µg/kg) or 0.9% saline for 15 days. To achieve complete NMB, 3.5 mg/kg rocuronium was administered on the sixteenth day. The recovery time to a train-of-four ratio ≥ 0.9 was measured to evaluate the complete recovery following the sugammadex injection. RESULTS: Among the groups, no significant differences were observed in the recovery time to a train-of-four ratio ≥ 0.9 following sugammadex administration (P = 0.531). The time to the second twitch of the train-of-four recovery following rocuronium administration indicated that the duration of NMB was significantly shorter in Group D than that in Groups C and P (P = 0.001). CONCLUSIONS: Chronic exposure to dexamethasone did not shorten the recovery time of sugammadex-induced NMB reversal. However, the findings of this study indicated that no adjustments to sugammadex dosage or route of administration is required, even in patients undergoing long-term steroid treatment.

Spontaneous pneumothorax after shoulder arthroscopy under general anesthesia: a case report.

A woman in her early 70s presented with a right fifth rib fracture along with left scapular body and glenoid fractures resulting from a traffic accident. She had no history of lung disease. The patient underwent multi-incisional video-guided arthroscopic fracture reduction and screw fixation in the right lateral decubitus position under general anesthesia, and surgery was followed by chest tube insertion. Left-sided pneumothorax was found during routine postoperative radiography despite the absence of relevant symptoms or signs such as hypoxia, chest pain, or respiratory difficulty. We herein report this unusual case with a brief literature review.

The effects of prewarming the I-gel on fitting to laryngeal structure.

PURPOSE: The supraglottic airway, I-gel (Intersurgical, Wokingham, United Kingdom), has a noninflatable cuff, which softens at body temperature to fit to laryngeal structure. The present study was performed to investigate the hypothesis that the cuff of I-gel can fit to laryngeal structure faster when prewarmed to body temperature than kept at room temperature. METHODS: A total of 180 adult patients were assigned to the warm group (90 patients) or the control group (90 patients). Anesthesia was induced with propofol, remifentanil, or fentanyl. Vecuronium or rocuronium was administered as a muscle relaxant. The I-gel was warmed to 37 °C before insertion in the warm group and it was in the room temperature (approximately 20 °C) in the control group. Insertion time, number of attempt for successful insertion, inspiratory pressure, leak pressure, and leak volume were compared between the 2 groups. RESULTS: Insertion time was 12.9 ± 9.3 seconds in the warm group and 14.5 ± 12.3 seconds in the control group. Number of attempt for insertion was 1 in 77 cases, 2 in 4 cases, and 3 in 1 case in the warm group and 1 in 79 cases and 2 in 7 cases in the control group. Inspiratory pressure, leak pressure, and leak volume were not significantly different between the 2 groups, whereas leak volume had a tendency to be smaller in the warm group. CONCLUSION: Prewarming the I-gel to body temperature did not have any significant benefits in comparison with the I-gel kept at room temperature.

Anesthetic care for electroconvulsive therapy.

Counselling and medication are often thought of as the only interventions for psychiatric disorders, but electroconvulsive therapy (ECT) has also been applied in clinical practice for over 80 years. ECT refers to the application of an electric stimulus through the patient's scalp to treat psychiatric disorders such as treatment-resistant depression, catatonia, and schizophrenia. It is a safe, effective, and evidence-based therapy performed under general anesthesia with muscle relaxation. An appropriate level of anesthesia is essential for safe and successful ECT; however, little is known about this because of the limited interest from anesthesiologists. As the incidence of ECT increases, more anesthesiologists will be required to better understand the physiological changes, complications, and pharmacological actions of anesthetics and adjuvant drugs. Therefore, this review focuses on the fundamental physiological changes, management, and pharmacological actions associated with various drugs, such as anesthetics and neuromuscular blocking agents, as well as the comorbidities, indications, contraindications, and complications of using these agents as part of an ECT procedure through a literature review and our own experiences.

Effects of hydrocortisone-presensitized sugammadex on recovery from neuromuscular blockade induced by rocuronium: a rodent in vivo study.

BACKGROUND: Sugammadex is a specific antagonist of aminosteroidal neuromuscular blocking agents with 1:1 binding to guest molecules. Sugammadex can also bind to other drugs having a steroid component in its chemical structure. In this in vivo experiment, we investigated the differences in the recovery of rocuronium-induced neuromuscular blockade using sugammadex pre-exposed with two different concentrations of hydrocortisone. METHODS: The sciatic nerves and tibialis anterior muscles of 30 adult Sprague-Dawley rats were prepared for the experiment. The sciatic nerves were stimulated using a train-of-four (TOF) pattern with indirect supramaximal stimulation at 20 s intervals. After 15 min of stabilization, a 250 µg loading dose and 125 µg booster doses of rocuronium were serially administered until > 95% depression of the first twitch tension of TOF stimulation (T1) was confirmed. The study drugs were prepared by mixing sugamadex with the same volume of three different stock solutions (0.9% normal saline, 10 mg/ml hydrocortisone, and 100 mg/ ml hydrocortisone). The recovery of rats from neuromuscular blockade was monitored by assessing T1 and the TOF ratio (TOFR) simultaneously until T1 was recovered to > 95% and TOFR to > 0.9. RESULTS: In the group injected with sugammadex premixed with a high concentration of hydrocortisone, statistically significant intergroup differences were observed in the recovery progression of T1 and TOFR (P < 0.050). CONCLUSIONS: When sugammadex was pre-exposed to a high dose of hydrocortisone only, recovery from neuromuscular blockade was delayed. Delayed recovery from neuromuscular blockade is not always plausible when sugammadex is pre-exposed to steroidal drugs.

Adverse events of sugammadex that occurred in a Korean population.

BACKGROUND: With increasing use, the incidence of adverse events associated with sugammadex, a neuromuscular blockade reverser, is increasing. This study aimed to identify and analyze cases of adverse events caused by sugammadex reported in Korean population. METHODS: Out of a total of 12 cases detected using various keywords in the Korean Journal of Anesthesia, Anesthesia and Pain Medicine (Seoul), KoreaMed, PubMed, EMBASE, Web of Science, and The Cochrane Library-CENTRAL from 2013 to December 2020, 10 cases directly associated with sugammadex were selected. RESULTS: Adverse events included five cases of anaphylaxis, one case of cardiac arrest, one case of profound bradycardia, one case of negative pressure pulmonary edema, and two cases of incomplete recovery. Three patients had American Society of Anesthesiologists physical status ≥ 3, two had emergency surgery, and two had a history of allergic reaction. Neuromuscular monitoring was applied in nine cases. The average dose of sugammadex was 2.87 mg/kg, and there were six cases in which one full vial was used, regardless of the state of neuromuscular recovery. Sugammadex was administered immediately after surgery in two cases, at train of four (TOF) 0 in four cases, at TOF 3 in one case, and after evaluation of the clinical signs only with no neuromuscular monitoring in one case. CONCLUSIONS: Even with neuromuscular monitoring, an excessive dose of sugammadex was observed. Given that adverse events tend to occur within 10 min of administration, continuous monitoring is important even after administration.