Comparison of the Effect of Sugammadex and Pyridostigmine on Postoperative Catheter-Related Bladder Discomfort: A Retrospective Matched Cohort Analysis.

Background and Objectives: As the use of sugammadex for reversing neuromuscular blockade during general anesthesia increases, additional effects of sugammadex have been reported compared to cholinesterase inhibitors. Here, we compare the incidence of postoperative catheter-related bladder discomfort (CRBD) between sugammadex and pyridostigmine/glycopyrrolate treatments for reversing neuromuscular blockade. Materials and Methods: We retrospectively analyzed patients aged ≥ 18 years who underwent surgery under general anesthesia, received sugammadex or pyridostigmine with glycopyrrolate to reverse neuromuscular blockade, and had a urinary catheter in the post-anesthesia care unit between March 2019 and February 2021. After applying the exclusion criteria, 1179 patients were included in the final analysis. The incidence and severity of CRBD were collected from post-anesthesia recovery records. Results: The incidence was 13.7% in the sugammadex group (n = 211) and 24.7% in the pyridostigmine group (n = 968). Following propensity score matching, 211 patients each were included in the pyridostigmine and sugammadex matched group (absolute standardized difference (ASD), 0.01-0.05). Compared to the pyridostigmine group, the odds ratio for CRBD occurring in the sugammadex group was 0.568 (95% confidential interval, 0.316-1.021, p = 0.059). Conclusions: Sugammadex has a similar effect on the occurrence of postoperative CRBD compared with pyridostigmine.

Retrospective lumbosacral CT analysis and prospective observational study of the ipsilateral tunnel view technique for fluoroscopy-guided selective S1 transforaminal epidural injection.

BACKGROUND: The purpose of this study was to retrospectively observe the anatomic relationship between dorsal S1 foramen (DS1F) and ventral S1 foramen (VS1F) through computed tomography (CT) analysis and to prospectively determine the optimal angle of ipsilateral tunnel view technique for performing S1 transforaminal epidural steroid injection (S1-TFESI). METHODS: The axial lumbosacral CTs taken between in 208 consecutive patients and the following measurements were obtained on both sides: (1) the α-angle was defined as an angle between a sagittal line passing through the center of the sacrum and an imaginary line passing through the center of DS1F, (2) the largest diameter of DS1F and VS1F. The fluoroscopy was adjusted to show the largest L5/S1 intervertebral disc space, which was defined as the cephalad angle, and tilted to the ipsilateral oblique side until the entrance of DS1F had a well-defined, round shape, which defined as the ß-angle in 40 humans. RESULTS: CT measurements showed that the α-angle was 26.3 ± 3.3 degrees (15-38 degrees) and the diameter of DS1F was 7.1 ± 0.7 mm (4-10.9 mm), which was significantly smaller than the diameter of VS1F, 10.1 ± 1.0 mm (7.2-13.8 mm). The ß-angle was 24 ± 4.6 degrees, which was not much different from the α-angle and the cephalad angle was 23 ± 4.6 degrees. The success rate of S1-TFESI was 100% and there were no procedure-related complications. CONCLUSIONS: The entrance of DS1F is easily identified with an ipsilateral 25 degrees-tunnel view technique while performing S1-TFESI, and it is a clinically applicable approach.

Development and validation of a difficult laryngoscopy prediction model using machine learning of neck circumference and thyromental height.

BACKGROUND: Predicting difficult airway is challengeable in patients with limited airway evaluation. The aim of this study is to develop and validate a model that predicts difficult laryngoscopy by machine learning of neck circumference and thyromental height as predictors that can be used even for patients with limited airway evaluation. METHODS: Variables for prediction of difficulty laryngoscopy included age, sex, height, weight, body mass index, neck circumference, and thyromental distance. Difficult laryngoscopy was defined as Grade 3 and 4 by the Cormack-Lehane classification. The preanesthesia and anesthesia data of 1677 patients who had undergone general anesthesia at a single center were collected. The data set was randomly stratified into a training set (80%) and a test set (20%), with equal distribution of difficulty laryngoscopy. The training data sets were trained with five algorithms (logistic regression, multilayer perceptron, random forest, extreme gradient boosting, and light gradient boosting machine). The prediction models were validated through a test set. RESULTS: The model's performance using random forest was best (area under receiver operating characteristic curve = 0.79 [95% confidence interval: 0.72-0.86], area under precision-recall curve = 0.32 [95% confidence interval: 0.27-0.37]). CONCLUSIONS: Machine learning can predict difficult laryngoscopy through a combination of several predictors including neck circumference and thyromental height. The performance of the model can be improved with more data, a new variable and combination of models.

Dexmedetomidine combined with suprascapular nerve block and axillary nerve block has a synergistic effect on relieving postoperative pain after arthroscopic rotator cuff repair.

PURPOSE: Suprascapular nerve block (SSNB) is the most commonly used block for the relief of postoperative pain from arthroscopic rotator cuff repair and can be used in combination with axillary nerve block (ANB). Dexmedetomidine (DEX) is a type of alpha agonist that can elongate the duration of regional block. The aim of this study was to compare the effects of the use of dexmedetomidine combined with SSNB and ANB with those of the use of SSNB and ANB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 h after arthroscopic rotator cuff repair. METHODS: Forty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single-center, double-blinded randomized controlled trial study. Twenty patients were randomly allocated to group 1 and received ultrasound-guided SSNB and ANB using a mixture of 0.5 ml (50 µg) of DEX and 9.5 ml of 0.75% ropivacaine preemptively. The other 20 patients were allocated to group 2 and underwent ultrasound-guided SSNB and ANB alone using a mixture of 0.5 ml of normal saline and 9.5 ml of ropivacaine. The visual analog scale (VAS) for pain and patient satisfaction (SAT) scores were postoperatively checked within 48 h. The plasma interleukin (IL)-6, IL-8, IL-1ß, cortisol, and serotonin levels were also postoperatively measured within 48 h. RESULTS: Group 1 showed a significantly lower mean VAS (visual analog scale of pain) score 1, 3, 6, 12, 18 and 24 h after operation, and a significantly higher mean SAT (patient satisfaction) score 1, 3, 6, 12, 18, 24 and 36 h after the operation than group 2. Group 1 showed a significantly lower mean plasma IL-8 level 1 and 48 h after the operation, and a significantly lower mean IL-1ß level 48 h after the operation than group 2. Group 1 showed a significantly lower mean plasma serotonin level 12 h after the operation than group 2. The mean timing of rebound pain in group 1 was significantly later than that in group 2 (36 h > 23 h, p = 0.007). Six patients each in groups 1 and 2 showed rebound pain. The others did not show rebound pain. CONCLUSIONS: Ultrasound-guided SSNA and ANB with DEX during arthroscopic rotator cuff repair resulted in a significantly lower mean VAS score and a significantly higher mean SAT score within 48 h after the operation than SSNB and ANB alone. Additionally, SSNB and ANB with DEX tended to result in a later mean timing of rebound pain accompanied by significant changes in IL-8, IL-1ß, and serotonin levels within 48 h after the operation. The present study could provide the basis for selecting objective parameters of postoperative pain in deciding the optimal use of medication for relieving pain. LEVEL OF EVIDENCE: Level I. TRIAL REGISTRATION: 2015-20, ClinicalTrials.gov Identifier: NCT04398589. IRB NUMBER: 2015-20, Hallym University Chuncheon Sacred Heart Hospital.

Effects of estimated glomerular filtration rate and diabetes mellitus on the effect of insulin for treating hyperkalemia during anesthesia.

PURPOSE: We analyzed the effectiveness of insulin for treating hyperkalemia (≥ 5 mEq/L) during anesthesia and the effects of the estimated glomerular filtration rate (eGFR) and diabetes mellitus (DM) on the insulin treatment. METHODS: Patients 18 years of age and older who received intravenous insulin lispro for hyperkalemia under general anesthesia between January 2010 and March 2020 were enrolled. We performed three propensity score matching analyses according to eGFR stages (eGFR ≥ 60 vs. 30 ≤ eGFR < 60 and eGFR ≥ 60 vs. eGFR < 30 mL/min/1.73 m2) and DM status. RESULTS: The study included 475 patients. For patients with hyperkalemia during surgery, the odds ratios [ORs] of failure to decrease potassium (K+) after insulin treatment were higher in patients with eGFR < 30 mL/min/1.73 m2 (adjusted OR 3.24; 95% confidence interval 1.38-7.64; P = 0.007) than in patients with eGFR ≥ 60 mL/min/1.73 m2. There was no significant difference in the ORs of patients with 30 ≤ eGFR < 60 mL/min/1.73 m2 and DM. CONCLUSION: The patients with a low eGFR had a higher incidence of K+ not decreasing after insulin treatment. Periodic assessment of K+ may be required during anesthesia.

Dexmedetomidine combined with interscalene brachial plexus block has a synergistic effect on relieving postoperative pain after arthroscopic rotator cuff repair.

PURPOSE: Interscalene brachial plexus block (ISB) is one of the most commonly used regional blocks in relieving postoperative pain after arthroscopic rotator cuff repair. Dexmedetomidine (DEX) is an alpha 2 agonist that can enhance the effect of regional blocks. The aim of this study was to compare the effects of DEX combined with ISB with ISB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 h after arthroscopic rotator cuff repair. METHODS: Fifty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single center, double-blinded randomized controlled trial study. Twenty-five patients were randomly allocated to group 1 and received ultrasound-guided ISB using a mixture of 1 ml (100 µg) of DEX and 8 ml of 0.75% ropivacaine preemptively. The other 25 patients were allocated to group 2 and underwent ultrasound-guided ISB alone using a mixture of 1 ml of normal saline and 8 ml of ropivacaine. The visual analog scale (VAS) for pain and patient satisfaction (SAT) scores were checked within 48 h postoperatively. The plasma interleukin (IL)-6, -8, -1ß, cortisol, and substance P levels were also measured within 48 h, postoperatively. RESULTS: Group 1 showed a significantly lower mean VAS score and a significantly higher mean SAT score than group 2 at 1, 3, 6, 12, and 18 h postoperatively. Compared with group 2, group 1 showed a significantly lower mean plasma IL-6 level at 1, 6, 12, and 48 h postoperatively and a significantly lower mean IL-8 level at 1, 6, 12, 24, and 48 h postoperatively. The mean timing of rebound pain in group 1 was significantly later than that in group 2 (12.7 h > 9.4 h, p = 0.006). CONCLUSIONS: Ultrasound-guided ISB with DEX in arthroscopic rotator cuff repair led to a significantly lower mean VAS score and a significantly higher mean SAT score within 48 h postoperatively than ISB alone. In addition, ISB with DEX showed lower mean plasma IL-6 and IL-8 levels than ISB alone within 48 h postoperatively, with delayed rebound pain. LEVEL OF EVIDENCE: I. TRIAL REGISTRATION: 2013-112, ClinicalTrials.gov Identifier: NCT02766556.

Intraoperative administration of dexmedetomidine reduced the postoperative catheter-related bladder discomfort and pain in patients undergoing lumbar microdiscectomy.

PURPOSE: We aimed to evaluate the effect of the intraoperative dexmedetomidine (DEX) on the incidence and severity of catheter-related bladder discomfort (CRBD) after non-urologic surgery. The secondary aim was to find the correlation between the levels of CRBD and postoperative pain sensation. METHODS: Adult male patients undergoing lumbar microdiscectomy were enrolled. Patients were randomized into two groups. After propofol administration, group D (n = 35) received DEX at a loading dose of 1 µg/kg over 10 min, followed by a continuous infusion of 0.3-0.5 µg/kg/h until the end of surgery. In group C (n = 35), an identical volume of 0.9% saline was infused in the same manner. Induction and maintenance of anesthesia were standardized. The incidence and severity of CRBD, postoperative pain, and adverse effects were assessed at 1, 3, and 6 h after surgery. RESULTS: The incidence of CRBD was significantly lower in group D than in group C at 1 h (34.3 vs. 62.9%, P = 0.017), 3 h (25.7 vs. 60%, P = 0.004), and 6 h (17.1 vs. 54.3%. P = 0.001) postoperatively. The severity of CRBD at 1, 3, and 6 h postoperatively was less in group D than in group C. Postoperative pain score was significantly lower in group D than in group C at 3 and 6 h postoperatively. Adverse events were comparable between two groups. There was a significant correlation between the severity of CRBD and postoperative pain score. CONCLUSIONS: Intraoperative administration of DEX is a safe and effective practice for the prevention of CRBD after lumbar microdiscectomy and can reduce postoperative pain.

Range of S-100ß levels during functional endoscopic sinus surgery with moderately controlled hypotension.

The aim of this study is to determine the range of S-100ß levels during functional endoscopic sinus surgery (FESS) when the mean arterial pressure (MAP) was controlled within 60-70 mmHg. After anesthesia induction with propofol and remifentanil, the patient was positioned in the reverse Trendelenburg position and MAP was controlled within 60-70 mmHg during surgery. For the S-100ß assay, blood was taken from a radial arterial catheter before (baseline) and at 20 (T 20) and 60 (T 60) min after setting the reverse Trendelenburg position and controlled hypotension, and at 60 (T post60) min after the end of the operation. In total, 34 patients completed the study. Baseline S-100ß was 0.00837 ± 0.00785 ng/mL. The levels at T 20 and T 60 were 0.02057 ± 0.01739 and 0.01987 ± 0.01145 ng/mL, respectively. The level of T post60 was 0.05436 ± 0.02318 ng/mL. The level at T 20 increased significantly versus the baseline level (P < 0.001); there were no significant differences between T 20 and T 60. The level at T post60 was significantly different versus T 20 and T 60 (P < 0.001). However, all S-100ß levels were within the normal range. S-100ß-a sensitive biomarker of cerebral ischemia-was within the normal range during FESS when moderate hypotension (MAP >60 mmHg) was provided. Thus, moderate hypotension would be seemed to be a safe and effective anesthetic technique for FESS without risk for cerebral ischemia.

Effects of arthroscopy-guided suprascapular nerve block combined with ultrasound-guided interscalene brachial plexus block for arthroscopic rotator cuff repair: a randomized controlled trial.

PURPOSE: The aim of this study was to compare the pain relieving effect of ultrasound-guided interscalene brachial plexus block (ISB) combined with arthroscopy-guided suprascapular nerve block (SSNB) with that of ultrasound-guided ISB alone within the first 48 h after arthroscopic rotator cuff repair. METHODS: Forty-eight patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled. The 24 patients in group 1 received ultrasound-guided ISB and arthroscopy-guided SSNB; the remaining 24 patients in group 2 underwent ultrasound-guided ISB alone. Visual analogue scale pain score and patient satisfaction score were checked at 1, 3, 6, 12, 18, 24, and 48 h post-operatively. RESULTS: Group 1 had a lower visual analogue scale pain score at 3, 6, 12, 18, 24, and 48 h post-operatively (1.7 < 2.6, 1.6 < 4.0, 3.5 < 5.8, 3.6 < 5.2, 3.2 < 4.2, 1.3 < 2.0), and a higher patient satisfaction score at 6, 12, 18, 24, and 36 h post-operatively than group 2 (7.8 > 6.0, 6.2 > 4.3, 6.4 > 5.1, 6.9 > 5.9, 7.9 > 7.1). Six patients in group 1 developed rebound pain twice, and the others in group 1 developed it once. All of the patients in group 2 had one rebound phenomenon each (p = 0.010). The mean timing of rebound pain in group 1 was later than that in group 2 (15.5 > 9.3 h, p < 0.001), and the mean size of rebound pain was smaller in group 1 than that in group 2 (2.5 > 4.0, p = 0.001). CONCLUSION: Arthroscopy-guided SSNB combined with ultrasound-guided ISB resulted in lower visual analogue scale pain scores at 3-24 and 48 h post-operatively, and higher patient satisfaction scores at 6-36 h post-operatively with the attenuated rebound pain compared to scores in patients who received ultrasound-guided ISB alone after arthroscopic rotator cuff repair. The combined blocks may relieve post-operative pain more effectively than the single block within 48 h after arthroscopic cuff repair. LEVEL OF EVIDENCE: Randomized controlled trial, Level I. ClinicalTrials.gov Identifier: NCT02424630.

Efficacy of direct arthroscopy-guided suprascapular nerve block after arthroscopic rotator cuff repair: a prospective randomized study.

PURPOSE: The purpose of this study was to evaluate the outcomes of arthroscopy-guided direct suprascapular nerve block performed after arthroscopic rotator cuff repair. METHODS: In the present prospective, randomized, double-blinded clinical study, 30 patients were divided into two groups: 15 patients (group I) were treated with arthroscopy-guided suprascapular nerve block using 10 mL 0.5 % ropivacaine with 1:200,000 epinephrine, and 15 patients (group II) were treated with placebo using 10 mL 0.9 % saline after arthroscopic rotator cuff repair. Patient pain levels were measured using the visual analog scale (VAS) at 1, 3, 6, 12, 18, and 24 h post-operatively. Additionally, the number of boluses and total amount of fentanyl dispensed by patient-controlled analgesia administration during the 24-h post-operative period were evaluated. RESULTS: VAS scores did not differ significantly between groups I and II during the 24-h post-operative period, but mean fentanyl bolus consumption was significantly less in group I compared with group II (p = 0.015). CONCLUSION: Arthroscopy-guided suprascapular nerve block at the end of a rotator cuff repair was safe and less time-consuming than expected. Although this procedure did not significantly reduce the post-operative pain, the post-operative need for fentanyl boluses as analgesia was reduced significantly, and it would be beneficial if this procedure involved a sensory branch of axillary nerve block or was performed at the beginning of the arthroscopic procedure. LEVEL OF EVIDENCE: Prospective, randomized, double-blinded clinical trial, Level I.

Patient preference and satisfaction with their involvement in the selection of an anesthetic method for surgery.

This prospective study aimed to evaluate the satisfaction of patients who participated in the decision-making process for selecting an anesthesia method for surgery; the patients' preferred role (active, collaborative or passive) in the decision-making; and the patients' preferred choice of anesthetic method. The study included 257 patients scheduled for simple elective surgeries involving the upper or lower extremities. During the preanesthetic visit, patients were informed regarding two methods of anesthesia for their surgeries, and participated in selecting one option. Of the 257 patients, 69.6% preferred a collaborative role, 18.3% and 12.1% preferred an active and a passive role, respectively. Among patients requiring surgery on an upper extremity and on a lower extremity, 64.3% and 51.3% expressed a preference for general anesthesia over regional anesthesia, respectively. After surgery, the majority of our patients were satisfied (93.4%) and felt respected (97.7%). Furthermore, the patients expressed a change in preference for assuming an active role (49.4%) and a collaborative role (43.6%) in the decision-making process for their future anesthesia needs. This study may help to promote patient centered care in a department of anesthesiology.

Effect of ultrasonographically guided axillary nerve block combined with suprascapular nerve block in arthroscopic rotator cuff repair: a randomized controlled trial.

PURPOSE: The aim of this study was to compare the results of ultrasonographically guided axillary nerve block (ANB) combined with suprascapular nerve block (SSNB) with those of SSNB alone on postoperative pain and satisfaction within the first 48 hours after arthroscopic rotator cuff repair. METHODS: Forty-two patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this study. Among them, 21 patients were randomly allocated to group 1 and received both SSNB and ANB with 10 mL ropivacaine. The other 21 patients were allocated to group 2 and received SSNB with 10 mL 0.75% ropivacaine and ANB with 10 mL saline. Visual analog scale (VAS) pain score, patient satisfaction (SAT), and lateral pain index (LPI) was checked at 1, 3, 6, 12, 18, 24, 36, and 48 hours postoperatively. RESULTS: Group 1 showed a significantly lower mean VAS score at postoperative 1, 3, 6, 12, 18, and 24 hours compared with group 2 (5.1 < 7.6, 4.4 < 6.3, 3.7 < 5.3, 3.2 < 4.5, 2.7 < 4.0, and 2.7 < 3.4, respectively). A significantly high mean SAT and low mean LPI was observed in group 1 at postoperative 1, 3, 6, 12, 18, 24, and 36 hours (4.9 > 2.4, 5.9 > 3.7, 6.3 > 5.0, 6.8 > 5.7, 7.3 > 6.2, 7.5 > 6.6, and 7.7 > 7.0, respectively), (1.1 < 3.0, 0.8 < 2.5, 0.7 < 2.0, 0.7 < 1.6, 0.6 < 1.3, 0.6 < 1.0, and 0.4 < 0.7, respectively). The frequency of rebound pain decreased in group 1 compared with group 2 (P = .032). In addition, rebound phenomenon showed a correlation with ANB on univariate logistic regression (P = .034; odds ratio, 0.246). CONCLUSIONS: Ultrasonographically guided ANB combined with SSNB in arthroscopic rotator cuff repair showed an improved mean VAS in the first 24 hours after surgery compared with SSNB alone. The mean SAT and LPI of the combined blocks were better than those of the single block within the first 36 hours. Ultrasonographically guided ANB combined with SSNB also decreased the rebound phenomenon. LEVEL OF EVIDENCE: Level I, randomized controlled trial.

Airway management of a patient with Mounier-Kuhn syndrome during general anesthesia - A case report.

BACKGROUND: Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by abnormal dilation of the trachea and main bronchi. MKS can be easily missed on chest X-rays, making diagnosis difficult. Under general anesthesia, challenges such as airway leakage or collapse during mechanical ventilation may complicate the achievement of adequate tidal volumes. CASES: A 94-year-old woman requiring emergency hemiarthroplasty of the hip under general anesthesia was admitted. Preoperative chest X-rays revealed dilation of the trachea and main bronchi, but the patient exhibited no respiratory symptoms. We diagnosed her with MKS and opted for an 8.0-mm-inner-diameter reinforced tracheal tube. We positioned the cuff in the subglottic area, inflating it while monitoring for air leakage. Throughout the surgery, adequate tidal volume was maintained. CONCLUSIONS: Anesthesiologists must conduct a comprehensive evaluation of patients with MKS, including a review of chest radiographs, and establish a meticulous anesthesia plan prior to surgery.

Influence of Curved Video Laryngoscope Blade Sizes and Patient Heights on Video Laryngoscopic Views: A Randomized Controlled Trial.

This study aimed to compare the video laryngoscope views facilitated by curved blades 3 and 4 with an exploration of the relationship between these views and patient height. Conducted as a randomized controlled trial, this study enrolled adults scheduled for surgery under general anesthesia. Intubation procedures were recorded, and the percentage of glottic opening was measured before tube insertion. Multivariate analysis validated the impact of various factors, including blade size and patient height, on the percentage of glottic opening scores. A total of 192 patients were included. The median percentage of glottic opening scores for curved blades 3 and 4 were 100 and 83, respectively (p < 0.001). The unstandardized coefficient indicated a significant negative impact of blade 4 on the percentage of glottic opening scores (-13, p < 0.001). In the locally estimated scatterplot smoothing analysis, blade 3 exhibited a steady rise in glottic opening scores with increasing height, whereas blade 4 showed a peak followed by a decline around 185 cm. The unstandardized coefficient of height showed no significant association (0, p = 0.819). The study observed superior laryngoscopic views with blade 3 compared to blade 4. However, no significant association was found between laryngoscopic views and patient height.

Extracorporeal membrane oxygenation for acute life-threatening neurogenic pulmonary edema following rupture of an intracranial aneurysm.

Neurogenic pulmonary edema (NPE) leading to cardiopulmonary dysfunction is a potentially life-threatening complication in patients with central nervous system lesions. This case report describes a 28-yr woman with life-threatening fulminant NPE, which was refractory to conventional respiratory treatment, following the rupture of an aneurysm. She was treated successfully with extracorporeal membrane oxygenation (ECMO), although ECMO therapy is generally contraindicated in neurological injuries such as brain trauma and diseases that are likely to require surgical intervention. The success of this treatment suggests that ECMO therapy should not be withheld from patients with life-threatening fulminant NPE after subarachnoid hemorrhage.

The effects of single-dose intravenous dexmedetomidine on hyperbaric bupivacaine spinal anesthesia.

PURPOSE: Dexmedetomidine, a selective α2-adrenoceptor agonist, has analgesic and sedative effects. The purpose of this study was to investigate the effects of small, single-dose intravenous dexmedetomidine administration after hyperbaric bupivacaine spinal anesthesia. METHODS: Sixty adult patients classified as American Society of Anesthesiologists physical status 1 or 2 and scheduled for lower extremity surgery under spinal anesthesia were studied. Patients were randomly assigned to one of three groups and administered hyperbaric intrathecal bupivacaine 12 mg. 5 min after spinal anesthesia, patients in groups 1, 2, and 3 received normal saline 10 ml, dexmedetomidine 0.25 µg/kg, and dexmedetomidine 0.5 µg/kg, respectively, over 10-min intravenous administration. The onset time, maximum block level, two-dermatome sensory regression time, duration of motor and sensory anesthesia, and side effects were assessed. RESULTS: The two-dermatome sensory regression time was significantly increased in groups 2 and 3. The duration of motor and sensory anesthesia was significantly increased in group 3. Onset time, maximum block level, level of sedation, and incidence of hypotension and treatment-needed bradycardia were no different among the groups. CONCLUSION: Single-dose intravenous dexmedetomidine 0.25-0.5 µg/kg, administered 5 min after intrathecal injection of hyperbaric bupivacaine, improved the duration of spinal anesthesia without significant side effects. This method may be useful for increasing the duration of spinal anesthesia, even after intrathecal injection of local anesthetics.

Harnessing Machine Learning for Prediction of Postoperative Pulmonary Complications: Retrospective Cohort Design.

Postoperative pulmonary complications (PPCs) are significant causes of postoperative morbidity and mortality. This study presents the utilization of machine learning for predicting PPCs and aims to identify the important features of the prediction models. This study used a retrospective cohort design and collected data from two hospitals. The dataset included perioperative variables such as patient characteristics, preexisting diseases, and intraoperative factors. Various algorithms, including logistic regression, random forest, light-gradient boosting machines, extreme-gradient boosting machines, and multilayer perceptrons, have been employed for model development and evaluation. This study enrolled 111,212 adult patients, with an overall incidence rate of 8.6% for developing PPCs. The area under the receiver-operating characteristic curve (AUROC) of the models was 0.699-0.767, and the f1 score was 0.446-0.526. In the prediction models, except for multilayer perceptron, the 10 most important features were obtained. In feature-reduced models, including 10 important features, the AUROC was 0.627-0.749, and the f1 score was 0.365-0.485. The number of packed red cells, urine, and rocuronium doses were similar in the three models. In conclusion, machine learning provides valuable insights into PPC prediction, significant features for prediction, and the feasibility of models that reduce the number of features.

Postoperative Nausea and Vomiting Prediction: Machine Learning Insights from a Comprehensive Analysis of Perioperative Data.

Postoperative nausea and vomiting (PONV) are common complications after surgery. This study aimed to present the utilization of machine learning for predicting PONV and provide insights based on a large amount of data. This retrospective study included data on perioperative features of patients, such as patient characteristics and perioperative factors, from two hospitals. Logistic regression algorithms, random forest, light-gradient boosting machines, and multilayer perceptrons were used as machine learning algorithms to develop the models. The dataset of this study included 106,860 adult patients, with an overall incidence rate of 14.4% for PONV. The area under the receiver operating characteristic curve (AUROC) of the models was 0.60-0.67. In the prediction models that included only the known risk and mitigating factors of PONV, the AUROC of the models was 0.54-0.69. Some features were found to be associated with patient-controlled analgesia, with opioids being the most important feature in almost all models. In conclusion, machine learning provides valuable insights into PONV prediction, the selection of significant features for prediction, and feature engineering.

Effect of the preoperative physical status on postoperative nausea and vomiting risk: a matched cohort study.

BACKGROUND: The American Society of Anesthesiologists Physical Status Classification System is commonly used for preoperative assessment. Patient physical status before surgery can play an important role in postoperative nausea and vomiting. However, the relationship between the physical status classification and postoperative nausea and vomiting has not been well defined. METHODS: Adults aged ≥ 18 years who underwent procedures under anesthesia between 2015 and 2020 were included in the study. We analyzed the relationship of postoperative nausea and vomiting with physical status classification score using propensity score matching and Cox hazard regression. Differences in intraoperative use of vasopressor and inotropes and invasive monitoring were investigated according to the classification. RESULTS: A total of 163,500 patients were included in the study. After matching, classification 1 versus 2 included 43,400 patients; 1 versus ≤ 3, 13,287 patients; 2 versus ≤ 3, 23,530 patients (absolute standardized difference, 0-0.06). Patients with physical status classification ≤ 3 had a significantly lower postoperative nausea and vomiting risk than those with classification 1-2 (physical status classification 1 vs. ≤ 3, hazard ratio 0.76 [0.71-0.82], P < 0.001; 2 versus ≤ 3, hazard ratio 0.86 [0.82-0.91], P < 0.001). Intraoperative use of vasopressor or inotrope and invasive monitoring were noted more in the high physical status classification than the low physical status classification (absolute standardized difference [0.19-1.25]). CONCLUSION: There were differences in intraoperative invasive monitoring and use of vasopressor or inotrope among the classifications, and a score of 3 or higher reduced the risk of postoperative nausea and vomiting more than a score of 1-2.

Effect of Intra- and Post-Operative Fluid and Blood Volume on Postoperative Pulmonary Edema in Patients with Intraoperative Massive Bleeding.

In patients with intraoperative massive bleeding, the effects of fluid and blood volume on postoperative pulmonary edema are uncertain. Patients with intraoperative massive bleeding who had undergone a non-cardiac surgery in five hospitals were enrolled in this study. We evaluated the association of postoperative pulmonary edema risk and intra- and post-operatively administered fluid and blood volumes in patients with intraoperative massive bleeding. In total, 2090 patients were included in the postoperative pulmonary edema analysis, and 300 patients developed pulmonary edema within 72 h of the surgery. The postoperative pulmonary edema with hypoxemia analysis included 1660 patients, and the condition occurred in 161 patients. An increase in the amount of red blood cells transfused per hour after surgery increased the risk of pulmonary edema (hazard ratio: 1.03; 95% confidence interval: 1.01-1.05; p = 0.013) and the risk of pulmonary edema with hypoxemia (hazard ratio: 1.04; 95% confidence interval: 1.01-1.07; p = 0.024). An increase in the red blood cells transfused per hour after surgery increased the risk of developing pulmonary edema. This increase can be considered as a risk factor for pulmonary edema.