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.

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.

Effect-site concentration of remimazolam at loss and recovery of responsiveness during general anesthesia: a simulation study.

BACKGROUND: The objective of this study was to investigate the effect-site concentration (Ce) of remimazolam at loss of response (LOR) and recovery of response (ROR) in patients underwent general anesthesia using simulation. In addition, the relationships between patient's factors and simulated Ce at LOR and ROR were examined. METHODS: The medical records of 81 patients who underwent elective surgery under general anesthesia using remimazolam with simulation of Ce between August 4, 2021 and October 12, 2021, were retrospectively reviewed. Remimazolam was administered as an induction dose of 6 or 12 mg/kg/h until the patient became unresponsive, followed by 0.3-2 mg/kg/ h to maintain BIS values below 60. Simultaneously, simulations of manual infusion mode were performed using Asan Pump software and the Ce of remimazolam was simulated using the Schüttler model. Whenever infusion rate of remimazolam was manually changed, the simulated Ce was confirmed almost simultaneously. LOR and ROR, defined as unresponsive and eye-opening to verbal commands, respectively, were recorded in the Asan Pump program. RESULTS: The median (1Q, 3Q) simulated Ce at LOR and ROR were 0.7 (0.5, 0.9) and 0.3 (0.2, 0.4) µg/ml, respectively. LOR was achieved in 1.9 min after remimazolam infusion with cumulative doses of 0.3 mg/kg. There was a significant relationship between age and simulated Ce at ROR (Ce at ROR = -0.0043 × age + 0.57, r = 0.30, P = 0.014). CONCLUSIONS: For optimal dosage adjustment, simulating Ce while administering remimazolam with a weight-based dose during anesthesia is helpful. Elderly patients may recover from anesthesia at lower Ce of remimazolam.

Unexpected pulmonary edema and cardiac arrest following wedge resection of spontaneous pneumothorax -A case report.

BACKGROUND: Reexpansion pulmonary edema is a rare but potentially lethal complication. We report a case of suspected reexpansion pulmonary edema that led to cardiac arrest. CASE: A 16-year-old male patient underwent wedge resection due to right pneumothorax. The patient showed pink frothy sputum three hours following surgery, and a chest x-ray showed right unilateral pulmonary edema. Thirteen hours following surgery, the patient continuously showed pink frothy sputum and presented with severe hypoxemia, tachypnea, and tachycardia. After transferring to the intensive care unit (ICU), he developed ventricular tachycardia. Cardiopulmonary resuscitation was performed for 32 min. Chest X-ray showed diffuse bilateral pulmonary edema. Extracorporeal membrane oxygenation was performed. During the 65 days of ICU care, the patient became mentally alert. However, follow-up echocardiography revealed severe heart failure. CONCLUSIONS: Rexpansion pulmonary edema can rapidly progress to diffuse bilateral pulmonary edema. Therefore, careful observation is required for the patients who show signs of pulmonary edema after reexpansion.

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.

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.

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.

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.

Nasotracheal intubation for airway management during anesthesia.

Nasotracheal intubation is used as a basic method for airway management, along with orotracheal intubation under anesthesia and intensive care. It has become an effective alternative method to orotracheal intubation with increased benefits of offering better mobility and surgical field in oral and maxillofacial surgery and possibly in trauma and critically ill patients. Nasotracheal intubation is performed through a relatively narrow nasal cavity; therefore, additional precautions are needed. Accordingly, nasotracheal intubation methods have evolved over the years with accumulated clinical experience and improved instruments to facilitate safe intubation with reduced complications. Therefore, in this review article, we summarize the basic anatomy of the nasal airways to clarify the precautions, delineate the history and development of various methods and instruments, and describe the indications, contraindications, complications, and preventive methods of nasotracheal intubation.

Effects of sevoflurane and adenosine receptor antagonist on the sugammadex-induced recovery from rocuronium-induced neuromuscular blockade in rodent phrenic nerve-hemidiaphragm tissue specimens.

Sevoflurane affects on the A1 receptor in the central nervous system and potentiates the action of neuromuscular blocking agents. In the present study, we investigated whether sevoflurane (SEVO) has the ability to potentiate the neuromuscular blocking effect of rocuronium and if the specific antagonist of adenosine receptor (SLV320) can reverse this effect. In this study, phrenic nerve-hemidiaphragm tissue specimens were obtained from 40 Sprague-Dawley (SD) rats. The specimens were immersed in an organ bath filled with Krebs buffer and stimulated by a train-of-four (TOF) pattern using indirect supramaximal stimulation at 20 s intervals. The specimens were randomly allocated to control, 2-chloroadenosine (CADO), SEVO, or SLV320 + SEVO groups. In the CADO and SLV320 + SEVO groups, CADO and SLV320 were added to the organ bath from the start to a concentration of 10 µM and 10 nM, respectively. We then proceeded with rocuronium-induced blockade of >95% depression of the first twitch tension of TOF (T1) and TOF ratio (TOFR). In the SEVO and SLV320 + SEVO groups, SEVO was added to the Krebs buffer solution to concentration of 400-500 µM for 10 min. Sugammadex-induced T1 and TOFR recovery was monitored for 30 min until >95% of T1 and >0.9 of TOFR were confirmed, and the recovery pattern was compared by plotting these data. T1 recovery in the SEVO and CADO groups was significantly delayed compared with the control and SLV320 + SEVO groups (p < .05). In conclusion, sevoflurane affects on the A1 receptor at the neuromuscular junction and delays sugammadex-induced recovery from neuromuscular blockade.

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.

The senior anesthesiologists and their medical profession in Korea: based on a survey.

BACKGROUND: The number of aging physicians is increasing as the global population ages. With aging, anesthesiologists would be expected to experience changes in their professional position. Therefore, we aimed to investigate the current professional status of Korean anesthesiologists aged over 60 years. METHODS: Registered anesthesiologists aged over 60 years in Korea were invited for a survey. The questionnaire addressed 10 subjects with 40 questions that focused on demographics, practical activities, work conditions, difficulties experienced due to physical changes caused by aging, and economic status. RESULTS: In total, 122 anesthesiologists responded to the survey (response rate: 15.7%). Of them, 30.3% were working in honorary and advisory positions at tertiary hospitals, while 19.7% were working as pain physicians. Majority of the respondents were working for 5 days a week (41.8%) and 6-8 hours/day (48.4%). Majority of them (79.5%) were generally satisfied with their present life. CONCLUSIONS: Majority of the senior anesthesiologists were working at general hospitals and they reported being "satisfied" with the current status of their life. However, the clinical practice and retirement strategies of senior anesthesiologists need to be evaluated systematically to prepare for the continuing gradual increase in the number of senior anesthesiologists.