Anesthesia and pain medicine最新文献

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.

Background: Magnetic resonance imaging (MRI) is a useful tool, but it can be difficult to perform in those with claustrophobia as it requires being enclosed in a noisy cylindrical space. Being in the prone position is essential to spread breast tissue. However, sedation in a prone position is challenging because of the possibility of respiratory depression and the difficulty in manipulating the airway.

Case: Four patients with claustrophobia were sedated using dexmedetomidine, has minimal effect on respiration. Dexmedetomidine also enables the patient's cooperation in assuming the prone position while infusing loading time. But dexmedetomidine requires a longer time to reach moderate sedation, an intermittent bolus of midazolam was required for rapid induction of moderate sedation. All exams were conducted successfully without any complications.

Conclusions: Administering dexmedetomidine and a midazolam bolus at the appropriate dose and timing will render MRI examinations in the prone position safe and satisfactory, without respiratory complications.

Background: The development of back pain following epidural analgesia is one reason for patient refusal of neuraxial analgesia. The primary endpoint of this study was to compare the incidence and severity of back pain following midline and paramedian epidural technique. The secondary endpoint was to identify the risk factors associated with the occurrence of back pain.

Methods: This prospective randomized study included 114 patients receiving thoracic epidural catheterization for pain management following upper abdominal or thoracic surgery. Patients were allocated to either the midline or the paramedian group by computer-generated randomization. An investigator who was blinded to the patient group interviewed patients at 24, and 48 h, and 3-5 days after surgery about the existence of back pain and its severity.

Results: The total incidence of back pain following epidural anesthesia was 23.8% in the midline group and 7.8% in the paramedian group. The numerical rating scale of back pain was not different between the two groups at 24 h and 4 days after surgery. The paramdian technique was associated with a lower incidence of back pain than the midline technique (95% confidence interval 0.05-0.74, odds ratio 0.2, P < 0.01). However, the number of attempts, surgical position, body mass index, and duration of surgery were not associated with back pain.

Conclusions: This study showed that the midline group of thoracic epidural analgesia demonstrated higher incidence of back pain than the paramedian group. However, the pain was mild in intensity and decreased with time in both groups.

Transtracheal jet ventilation can be used for resuscitation of partial airway obstruction. A prerequisite for jet ventilation is that at least a minimum airway opening for gas escape must be secured. Therefore, another option should be considered in cases of complete airway obstruction. The following methods or devices has been used under cricothyrotomy using an intravenous cannula: 1) Ambu (bag valve mask) bagging, 2) Ventrain® , 3) Rapid-O2 oxygen insufflation device (Rapid-O2), and 4) jet ventilation using a dual lumen catheter. During Ambu bagging, extraordinarily high insufflation pressure is required to force oxygen through the cannula. When using a 12-G cannula, long and slow positive-pressure ventilations (10-12 breaths/min) are required, which makes it extremely difficult to compress the bag. Therefore, a 10-G or larger is recommended. Ventrain® is an expiratory assist device capable of forcibly expelling insufflated oxygen through a transtracheal cannula. It is recommended to adjust the inspiratory and expiratory times while observing the chest wall movements. Rapid-O2 is a rescue oxygenation device with adequate ventilation of less importance; therefore, the resulting hypercarbia is inevitable. A 14-G cannula is used. Lastly, jet ventilation using a dual-lumen catheter with a 16-G inflow lumen and 10-G outflow lumen was used to obtain both oxygenation and ventilation. However, the addition of the outer diameters of 16-G and 10-G results in an outer diameter of 5.1 mm, which is too large to puncture the cricothyroid membrane. In conclusion, Ventrain® is considered the most ideal device for use among the devices developed to date.

Background: Postpartum hemorrhage (PPH) is a major cause of maternal mortality and the risk factors for PPH differ among studies. In this large-scale study, we investigated whether the anesthetic method used was associated with PPH after cesarean section.

Methods: We extracted data on cesarean sections performed between January 2008 and June 2013 from the National Health Insurance Service database. The anesthetic methods were categorized into general, spinal and epidural anesthesia. To compare the likelihood of PPH among deliveries using different anesthetic methods, crude and adjusted odds ratios (ORs) and 95% confidence intervals were calculated using logistic regression analysis.

Results: Data from 330,324 cesarean sections were analyzed, and 21,636 cases of PPH were identified. Univariate analysis showed that general and epidural anesthesia increased the risk of PPH compared to spinal anesthesia. The OR for PPH was highest for morbidly adherent placenta, followed by placenta previa, placental abruption, and hypertension. When other clinical covariates were controlled for, general and epidural anesthesia still remained significant risk factors for PPH compared to spinal anesthesia.

Conclusions: This study showed that general and epidural anesthesia elevated the risk of PPH compared to spinal anesthesia during cesarean section. Since we could not consider the potential bias of group differences in indications, more in-depth clinical trials are needed to validate our findings. Obstetric factors such as placental abnormalities had high odds ratios and thus are more important than the choice of anesthetic method, which should be based on the patient's clinical condition and institutional resources.

Background: We aimed to explore the distribution of intraoperative lactic acid (LA) level during liver transplantation (LT) and determine the optimal cutoff values to predict post-LT 30-day and 90-day mortality.

Methods: Intraoperative LA data from 3,338 patients were collected between 2008 to 2019 and all-cause mortalities within 30 and 90 days were retrospectively reviewed. Of the three LA levels measured during preanhepatic, anhepatic, and neohepatic phase of LT, the peak LA level was selected to explore the distribution and predict early post-LT mortality. To determine the best cutoff values of LA, we used a classification and regression tree algorithm and maximally selected rank statistics with the smallest P value.

Results: The median intraoperative LA level was 4.4 mmol/L (range: 0.5-34.7, interquartile range: 3.0-6.2 mmol/L). Of the 3,338 patients, 1,884 (56.4%) had LA levels > 4.0 mmol/L and 188 (5.6%) had LA levels > 10 mmol/L. Patients with LA levels > 16.7 mmol/L and 13.5-16.7 mmol/L showed significantly higher 30-day mortality rates of 58.3% and 21.2%, respectively. For the prediction of the 90-day mortality, 8.4 mmol/L of intraoperative LA was the best cutoff value.

Conclusions: Approximately 6% of the LT recipients showed intraoperative hyperlactatemia of > 10 mmol/L during LT, and those with LA > 8.4 mmol/L were associated with significantly higher early post-LT mortality.

Background: The presence of a urinary catheter, postoperative pain, and postoperative nausea and vomiting are risk factors for emergence agitation (EA). Antimuscarinic agents are primary agents used in the prevention and treatment of urinary catheter-related bladder discomfort. Chlorpheniramine has antimuscarinic, antinociceptive, and antiemetic effects. This retrospective study investigated the role of chlorpheniramine in EA prevention following ureteroscopic stone surgery.

Methods: Of 110 adult patients who underwent ureteroscopic stone surgery under general anesthesia between January and December 2019, the medical records of 93 patients were analyzed retrospectively. The patients were divided into control (n = 52) and chlorpheniramine (n = 41) groups according to the receipt of intravenous chlorpheniramine before the induction of anesthesia. The incidence and severity of EA were compared between the groups as primary and secondary endpoints, respectively. The effects of chlorpheniramine on the requirement for inhalation anesthetic (desflurane) during surgery, changes in mean blood pressure and heart rate during emergence, and adverse events were also compared.

Results: The incidence (21.2% in the control group, 24.4% in the chlorpheniramine group) and severity of EA did not differ between groups. The intraoperative requirement for desflurane, changes in mean blood pressure and heart rate during emergence, and adverse events were also similar between groups.

Conclusions: Chlorpheniramine was not associated with a decrease in EA incidence or severity in patients who underwent ureteroscopic stone surgery.

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.

Background: Myasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.

Methods: We retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0-T8) and collected respiratory and hemodynamic variables, including arterial O2 index (PaO2/FiO2).

Results: SpO2 at T1-T3 and T8 was significantly lower in group D than in group S. The FiO2 in group S was lower than that in group D at all time points. The number of PaO2/FiO2 ≤ 300 and PaO2/FiO2 ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D.

Conclusions: This retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.