Korean clinical practice guidelines for diagnostic and procedural sedation.

Safe and effective sedation depends on various factors, such as the choice of sedatives, sedation techniques used, experience of the sedation provider, degree of sedation-related education and training, equipment and healthcare worker availability, the patient's underlying diseases, and the procedure being performed. The purpose of these evidence-based multidisciplinary clinical practice guidelines is to ensure the safety and efficacy of sedation, thereby contributing to patient safety and ultimately improving public health. These clinical practice guidelines comprise 15 key questions covering various topics related to the following: the sedation providers; medications and equipment available; appropriate patient selection; anesthesiologist referrals for high-risk patients; pre-sedation fasting; comparison of representative drugs used in adult and pediatric patients; respiratory system, cardiovascular system, and sedation depth monitoring during sedation; management of respiratory complications during pediatric sedation; and discharge criteria. The recommendations in these clinical practice guidelines were systematically developed to assist providers and patients in sedation-related decision making for diagnostic and therapeutic examinations or procedures. Depending on the characteristics of primary, secondary, and tertiary care institutions as well as the clinical needs and limitations, sedation providers at each medical institution may choose to apply the recommendations as they are, modify them appropriately, or reject them completely.

Mortality scoring systems for liver transplant recipients: before and after model for end-stage liver disease score.

The mortality scoring systems for patients with end-stage liver disease have evolved from the Child-Turcotte-Pugh score to the model for end-stage liver disease (MELD) score, affecting the wait list for liver allocation. There are inherent weaknesses in the MELD score, with the gradual decline in its accuracy owing to changes in patient demographics or treatment options. Continuous refinement of the MELD score is in progress; however, both advantages and disadvantages exist. Recently, attempts have been made to introduce artificial intelligence into mortality prediction; however, many challenges must still be overcome. More research is needed to improve the accuracy of mortality prediction in liver transplant recipients.

Efficacy of preoxygenation with end-tidal oxygen when using different oxygen concentrations in patients undergoing general surgery: a single-center retrospective observational study.

BACKGROUND: Preoxygenation is a simple but very important procedure for preventing arterial desaturation. A higher fraction of inspired oxygen (FiO2) increases atelectasis and 80% oxygen results in significantly less atelectasis than 100% oxygen. We investigated whether there was a difference in the duration of adequate preoxygenation when using 100% and 80% oxygen. The proportion of patients for whom >3 min was required to achieve adequate preoxygenation was also investigated. METHODS: The VitalDB database of patients underwent general surgery between February 1, 2021 and November 12, 2021 was reviewed. The time between the start of preoxygenation and the point where a 10% difference between FiO2 and end-tidal oxygen (EtO2) was defined as the preoxygenation time. The patients were classified into 100% and 80% groups according to the oxygen concentration. Propensity score matching (PSM) was performed to control for potential confounding factors. RESULTS: Only 330 of the 1,377 patients had sufficient data for analysis: 179 in the 80% group and 151 in the 100% group. After PSM, 143 patients in each group were analyzed. The median preoxygenation time was 143 s [interquartile range (IQR): 120.5-181.5 s] and 144 s (IQR: 109.75-186.25 s) in the 80% and 100% groups, respectively [P=0.605; median difference =-1 s; 95% confidence interval (CI): -13 to 10]. Of the patients, 27% required >3 min for adequate preoxygenation. CONCLUSIONS: No difference in preoxygenation time was found between the 80% and 100% groups. For some patients, breathing for 3 min is not sufficient for adequate preoxygenation. EtO2 monitoring aids evaluation of whether preoxygenation was adequate.

Successful extracorporeal membrane oxygenation in a patient with central airway obstruction due to an endotracheal mass.

Extracorporeal membrane oxygenation (ECMO) assists blood circulation and gas exchange via a heart-lung machine. ECMO is used mainly in intensive care units as bridging therapy until heart and respiratory failure can be addressed or until transplantation can be performed. ECMO is sometimes used during surgery under general anaesthesia, depending on the patient's underlying diseases and the nature of the operation. If the oxygen supply and carbon dioxide removal capacity are limited, venovenous (VV)-ECMO can be helpful. Here, we describe the use of VV-ECMO for surgical resection of an endotracheal mass through rigid bronchoscopy in a patient who developed decompensating dyspnoea due to central airway obstruction (CAO).

Sedation for magnetic resonance imaging in the prone position - A report of four cases.

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.

Prediction of blood pressure changes associated with abdominal pressure changes during robotic laparoscopic low abdominal surgery using deep learning.

BACKGROUND: Intraoperative hypertension and blood pressure (BP) fluctuation are known to be associated with negative patient outcomes. During robotic lower abdominal surgery, the patient's abdominal cavity is filled with CO2, and the patient's head is steeply positioned toward the floor (Trendelenburg position). Pneumoperitoneum and the Trendelenburg position together with physiological alterations during anesthesia, interfere with predicting BP changes. Recently, deep learning using recurrent neural networks (RNN) was shown to be effective in predicting intraoperative BP. A model for predicting BP rise was designed using RNN under special scenarios during robotic laparoscopic surgery and its accuracy was tested. METHODS: Databases that included adult patients (over 19 years old) undergoing low abdominal da Vinci robotic surgery (ovarian cystectomy, hysterectomy, myomectomy, prostatectomy, and salpingo-oophorectomy) at Soonchunhyang University Bucheon Hospital from October 2018 to March 2021 were used. An RNN-based model was designed using Python3 language with the PyTorch packages. The model was trained to predict whether hypertension (20% increase in the mean BP from baseline) would develop within 10 minutes after pneumoperitoneum. RESULTS: Eight distinct datasets were generated and the predictive power was compared. The macro-average F1 scores of the datasets ranged from 68.18% to 72.33%. It took only 3.472 milliseconds to obtain 39 prediction outputs. CONCLUSIONS: A prediction model using the RNN may predict BP rises during robotic laparoscopic surgery.

Intraoperative use of noninvasive ventilation during spinal anaesthesia in patients with severe chronic obstructive pulmonary disease undergoing orthopaedic surgery: A case report.

Compared with invasive mechanical ventilation, noninvasive ventilation (NIV) improves patient comfort and neurocognitive function; and reduces the likelihood of nosocomial infections and the need for sedation. NIV can also be used perioperatively to prevent postoperative pulmonary complications. This current report describes a case of a 64-year-old female patient with chronic obstructive pulmonary disease and chronic respiratory failure that underwent spinal anaesthesia during surgery. She was sedated with propofol. She brought her home ventilator equipment to the operating room and it was used in biphasic-positive airway pressure mode for immediate treatment of respiratory depression.

Apnoeic oxygenation using transnasal humidified rapid-insufflation ventilatory exchange during rigid bronchoscopy: a report of four cases.

General anaesthesia with a muscle relaxant is usually performed for rigid bronchoscopy (RB), but ventilation is challenging due to large amounts of leakage. Optiflow™ supplies 100% humidified, warmed oxygen at a rate of up to 70 l/min and this high flow rate may overcome the leakage problem. This case report describes four patients that were scheduled for RB. The lung lesions were all located below the carina, so a bronchial tube was inserted under general anaesthesia. Once a large amount of leakage was confirmed by manual ventilation, Optiflow™ was connected to the bronchial tube (flow rate, 70 l/min). All of the ports of the bronchoscopy were left open to prevent the risk of outlet obstruction. Oxygenation was well maintained with stable vital signs throughout the procedures, which took up to 34 min without airway intervention. There were no occurrences of cardiac arrhythmia or changes in the electrocardiograms. Respiratory acidosis recovered after emergence, which was confirmed by arterial blood gas analysis in all cases. Apnoeic oxygenation using Optiflow™ was applied successfully during RB. Applying Optiflow™ could make cases of difficult ventilation during RB much easier for the anaesthetist. Larger studies need to demonstrate the efficacy and safety of this technique.

Impact of Bilateral Subcostal Plus Lateral Transversus Abdominis Plane Block on Quality of Recovery After Laparoscopic Cholecystectomy: A Randomized Placebo-Controlled Trial.

BACKGROUND: Previous research has not evaluated the potential effect of transversus abdominis plane (TAP) block on quality of recovery following laparoscopic cholecystectomy. Therefore, we investigated whether addition of the bilateral subcostal and lateral TAP (bilateral dual TAP [BD-TAP]) blocks to multimodal analgesia would improve the quality of recovery as assessed with the Quality of Recovery-40 (QoR-40). METHODS: Patients age 18 to 60 years who were scheduled to undergo elective laparoscopic cholecystectomy were randomized to the BD-TAP or control group. The BD-TAP group received the BD-TAP block with multimodal analgesia under general anesthesia, using 0.25% ropivacaine, and the control group was treated with the same method, except that they received the sham block using 0.9% normal saline. Both groups had the same multimodal analgesia regimen, consisting of intravenous dexamethasone, propacetamol, ibuprofen, and oxycodone. The primary outcome was the QoR-40 score at 24 hours after surgery. Data were analyzed using the independent t test, Mann-Whitney U test, χ2 test, and Fisher exact test. RESULTS: Thirty-eight patients in each group were recruited. The mean QoR-40 score decreased by 13.6 (95% confidence interval [CI], 8.3-18.8) in the BD-TAP group and 15.6 (95% CI, 6.7-24.5) in the control group. The postoperative QoR-40 score at 24 hours after surgery did not differ between the 2 groups (BD-TAP group, median [interquartile range], 170.5 [152-178]; control group, 161 [148-175]; median difference, 3 [95% CI, -5 to 13]; P = .427). There were no differences between the 2 groups in the pain dimension of the QoR-40: 30.5 (95% CI, 27-33) in the BD-TAP group and 31 (95% CI, 26-32) in the control group; median difference was 0 (95% CI, -2 to 2); P = .77. CONCLUSIONS: Our results indicate that the BD-TAP block does not improve the quality of recovery or analgesic outcomes following laparoscopic cholecystectomy. Our results do not support the routine use of the BD-TAP block for this surgery.

Successful use of ultrasound-guided peripheral nerve block for lower limb surgery in a patient with heart failure with reduced ejection fraction: a case report.

The number of patients with heart failure with reduced ejection fraction (HFrEF) is increasing. These patients have a reduced cardiorespiratory reserve. Therefore, preoperative evaluation is essential to determine the best type of anaesthesia to use in patients with HFrEF. A 70-year-old man with HFrEF was scheduled to undergo debridement of skin necrosis due to thrombotic occlusion of the right common iliac artery. He had undergone wound dressing changes under local anaesthesia every other day for several months, and treatment for heart failure was on-going. A sciatic nerve and fascia iliaca compartment block was performed under ultrasound guidance because of the patient's cardiopulmonary function. After confirming adequate sensory blockage, surgery was performed without any haemodynamic instability or complications. Thereafter, debridement was performed twice more using the same block technique, and a skin autograft was also successfully performed. We successfully performed an ultrasound-guided sciatic nerve and fascia iliaca compartment block in a patient with HFrEF who was scheduled to undergo lower limb surgery. Peripheral nerve block is an alternative option for patients with HFrEF.

A novel application of Transnasal Humidified Rapid Insufflation Ventilatory Exchange via the oral route in morbidly obese patient during monitored anesthesia care - A case report.

BACKGROUND: Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) is used to improve oxygenation, with the added benefit of a smaller increase in CO2 if self-respiration is maintained with THRIVE. Despite these advantages, the use of THRIVE through a nasal cannula is limited in situations such as epistaxis or a basal skull fracture. CASE: We successful used THRIVE, through the oral route under general anesthesia with spontaneous breathing in a morbidly obese patient (weight, 148 kg; height, 183 cm; body mass index, 44.2 kg/m2) who received transnasal steroid injections due to subglottic stenosis. CONCLUSIONS: THRIVE through the oral route may be an effective novel option, although further studies are needed.

Ultrasound-guided pulsed radiofrequency treatment for distal suprascapular neuropathy: A case report.

RATIONALE: Suprascapular neuropathy is a rare cause of shoulder pain, and patients usually presents with posterosuperior shoulder pain and weakness on forward flexion and external rotation. Suprascapular neuropathy associated with rotator cuff pathology has received attention as an emerging cause of this condition. Suprascapular nerve (SSN) block can be used in these patients, and pulsed radio frequency (PRF) can be applied to achieve a long-term effect. Several studies have reported on PRF treatment of the SSN for shoulder pain, but most applied treatment to the nerve trunk under the transverse scapular ligament. This report describes a patient with suprascapular neuropathy treated with selective application of PRF to the distal SSN under ultrasound guidance. PATIENT CONCERNS: A 68-year-old woman suffered from right posterior shoulder pain after traumatic full thickness rotator cuff tear. Her pain was not diminished despite of 2 surgeries. DIAGNOSES: She was diagnosed with entrapment of the distal SSN in the spino-glenoid (SGN) notch and suprascapular neuropathy. INTERVENTIONS: She underwent surgery to decompress the entrapped SSN in the SGN. After that, we applied PRF on the distal SSN under ultrasound guidance for persistent pain. This treatment was repeated 3 times. OUTCOMES: PRF treatment resulted in a slight reduction in the visual analogue scale (VAS) pain score from 7-8/10 to 5-6/10 at the 2 weeks follow-up, and to 2-3/10 at the 1 month follow-up. The reduction in pain was maintained at the 1 year follow-up. LESSONS: PRF treatment of the SSN is typically approached from the main branch in the suprascapular notch. We selectively applied PRF to the distal SSN close to the SGN. This technique was safe and effective.

A case of one-lung ventilation using a single-lumen tube placed under fiberoptic bronchoscopic guidance in a 4-year-old child: A case report.

RATIONALE: One-lung ventilation (OLV) is essential for adequate visualization and exposure of the surgical site via a videoscopic approach. Although many instruments facilitating OLV are available, the choice is limited in pediatric patients. PATIENT CONCERNS: A 4-year-old female (weight: 18.6 kg, height: 100 cm) was admitted via our pediatric outpatient clinic because of recurrent hemoptysis, 2 weeks in duration. She had no medical or surgical history. DIAGNOSIS: Contrast-enhanced computed tomography (CT) revealed a 4.5-cm-diameter mass in the left, lower lung lobe. She was diagnosed with a congenital pulmonary airway malformation (CPAM). INTERVENTIONS: She was scheduled for emergency lobectomy via video-assisted thoracoscopic surgery (VATS). To ensure successful VATS, OLV was essential. As our hospital lacked a small-diameter fiberoptic bronchoscope and a proper bronchial blocker, we decided to use single-lumen tube (SLT) with adult fiberoptic bronchoscope. OUTCOMES: We performed successful bronchoscopic-guided OLV using a SLT. We aligned the tube to the right upper lobar bronchus and Murphy eye to prevent obstruction of the right upper lobe bronchus. At the end of surgery, the endotracheal tube lumen had been narrowed by blood clots, we decided to exchange the tracheal tube. The tube was immediately exchanged. After re-intubation, the pulse oximetry (SpO2) then gradually increased. LESSONS: Appropriate preparation and careful management should be considered to perform OLV in pediatric patients without significant complications.

Effects of continuous positive airway pressure in patients at high risk of obstructive sleep apnea during propofol sedation after spinal anesthesia.

In patients with obstructive sleep apnea, short-term use of a continuous positive airway pressure mask improves oxygenation, decreases the apnea-hypopnea index, and reduces hemodynamic instability. In this study, we investigated the effects of use of a continuous positive airway pressure mask in patients at high risk of obstructive sleep apnea during propofol sedation after spinal anesthesia. Forty patients who underwent propofol sedation after spinal anesthesia for transurethral bladder or prostate resection with a STOP-Bang score of 3 or more were enrolled in this study. Patients were randomly divided into two groups: a simple oxygen mask group (n = 20) and a continuous positive airway pressure mask group (n = 20). After spinal anesthesia, propofol was injected at a target concentration of 1.3 mcg/ml via a target concentration control injector. ApneaLink™ was applied to all patients. Patients in the simple oxygen mask group were administered oxygen at a rate of 6 L/min through a simple facial mask. Patients in the CPAP mask group were connected to a pressurizer, and oxygen (6 L/min, 5-15 cm H2O) was administered. Blood pressure, heart rate, respiratory rate, and oxygen saturation were recorded preoperatively, after spinal anesthesia, and every 5 min after the injection of propofol to observe hemodynamic changes. Apnea-hypopnea index was estimated using ApneaLink™. There were no significant differences in hemodynamic changes between the two groups. Apnea-hypopnea index was significantly reduced in the continuous positive airway pressure mask group compared to the simple facial mask group. Application of a continuous positive airway pressure mask in a patient at high risk of obstructive sleep apnea can lower the incidence of obstructive sleep apnea during sedation without a significant effect on hemodynamic stability.

Analysis of caudal epidurogram in single center: A preliminary study of lumbar radiculopathy management.

A caudal epidural block involves placing a needle through the sacral hiatus and delivering medication into the epidural space. The procedure is safe and simple, but failure rates can be as high as 25%. The purpose of this study was to investigate the success rate of caudal epidural block by analyzing needle placement and dye flow pattern.We retrospectively analyzed the medical records of patients who underwent caudal epidural block under spinal stenosis. A case was defined as a failure if it met at least one of the following four criteria: the epidural needle was not placed correctly inside the caudal canal; blood regurgitation or aspiration in the needle was observed; the contrast dye was injected into a blood vessel; or a large amount of the dye leaked into the sacral foramen or did not reach the L5-S1 level.At least 1 failure criterion was observed in 14 cases (17.7%), while none of the failure criteria were satisfied in 65 successful cases (82.3%).No matter how experienced the anesthesiologist may be, delivery of adequate therapeutic agent is not achieved in approximately 20% of cases. Therefore, we recommend fluoroscopy-guided needle placement and confirmation by radio-contrast epidurograpy as the best choice.

Reduced Hemidiaphragmatic Paresis With a "Corner Pocket" Technique for Supraclavicular Brachial Plexus Block: Single-Center, Observer-Blinded, Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Hemidiaphragmatic paresis is common after supraclavicular brachial plexus block (SCBPB). In this randomized trial, we compared the incidence of hemidiaphragmatic paresis in patients who had local anesthetic injected primarily in the corner pocket (defined as the intersection of the first rib and subclavian artery) during SCBPB with that of patients who underwent injection primarily inside the neural cluster. METHODS: Thirty-six patients scheduled for right elbow, forearm, wrist, or hand surgery under SCBPB (using 12.5 mL of 0.75% ropivacaine and 12.5 mL of 2% lidocaine with 1:200,000 epinephrine) were randomly assigned to 1 of 2 groups. In group CP, local anesthetic was injected primarily in the corner pocket (20 mL) and secondarily inside the neural cluster (5 mL). In group NC, local anesthetic was deposited primarily inside the neural cluster (20 mL) and secondarily in the corner pocket (5 mL). The primary outcome was the incidence of hemidiaphragmatic paresis, as measured by M-mode ultrasonography 30 minutes after SCBPB. RESULTS: The incidence of hemidiaphragmatic paresis was significantly lower in group CP than in group NC (27.8% vs 66.7%, P = 0.019). The median decreases in forced expiratory volume at 1 second (7.5% [interquartile range, 3.3%-17.1%] vs 24.4% [interquartile range, 10.2%-31.2%]; P = 0.010) and forced vital capacity (6.4% [interquartile range, 3.3%-11.1%] vs 19.3% [interquartile range, 13.7%-33.2%]; P = 0.001) were also lower in group CP than in group NC. CONCLUSIONS: The incidence of hemidiaphragmatic paresis was effectively reduced when local anesthetic was injected primarily in the corner pocket during right-sided SCBPB. However, the 28% incidence of hemidiaphragmatic paresis associated with the corner pocket technique may still represent a prohibitive risk for patients with preexisting pulmonary compromise. CLINICAL TRIAL REGISTRATION: This study was registered at Clinical Trial Registry of Korea, identifier KCT0001769.

Exposure of isoflurane-treated cells to hyperoxia decreases cell viability and activates the mitochondrial apoptotic pathway.

Isoflurane has either neuroprotective or neurotoxic effects. High-dose oxygen is frequently used throughout the perioperative period. We hypothesized that hyperoxia will affect cell viability of rat pheochromocytoma (PC12) cells that were exposed to isoflurane and reactive oxygen species (ROS) may be involved. PC12 cells were exposed to 1.2% or 2.4% isoflurane for 6 or 24h respectively, and cell viability was evaluated. To investigate the effects of hyperoxia, PC12 cells were treated with 21%, 50%, or 95% oxygen and 2.4% isoflurane for 6h, and cell viability, TUNEL staining, ROS production, and expression of B-cell lymphoma 2 (BCL-2), BCL2-associated X protein (BAX), caspase-3 and beta-site APP cleaving enzyme (BACE) were measured. ROS involvement was evaluated using the ROS scavenger 2-mercaptopropiopylglycine (MPG). The viability of cells exposed to 2.4% isoflurane was lower than that of cells exposed to 1.2% isoflurane. Prolonged exposure (6h vs. 24h) to 2.4% isoflurane resulted in a profound reduction in cell viability. Treatment with 95% (but not 50%) oxygen enhanced the decrease in cell viability induced by 2.4% isoflurane alone. Levels of ROS, Bax, caspase-3 and BACE were increased, whereas expression of Bcl-2 was decreased, in cells treated with 95% oxygen plus 2.4% isoflurane compared with the control and 2.4% isoflurane plus air groups. MPG attenuated the effects of oxygen and isoflurane. In conclusion, isoflurane affects cell viability in a dose- and time-dependent manner. This effect is augmented by hyperoxia and may involve ROS, the mitochondrial apoptotic signaling pathway, and ß-amyloid protein.

Effects of partial neuromuscular blockade on lateral spread response monitoring during microvascular decompression surgery.

OBJECTIVE: We evaluated the effect of partial neuromuscular blockade (NMB) and no NMB on successful intraoperative monitoring of the lateral spread response (LSR) during microvascular decompression (MVD) surgery. METHODS: Patients were randomly allocated into one of three groups: the TOF group, the NMB was targeted to maintain two counts of train-of-four (TOF); the T1 group, maintain the T1/Tc (T1: amplitude of first twitch, Tc: amplitude of baseline twitch) ratio at 50%; and the N group, no relaxants after tracheal intubation. Successful LSR monitoring was defined as effective baseline establishment and maintenance of the LSR until dural opening. RESULTS: The success rate of LSR monitoring was significantly lower in the TOF group. But, there was no significant difference between T1 and N. The detection rate of spontaneous free-run electromyography (EMG) activity was significantly higher in the N group compared with the TOF and T1 groups. CONCLUSIONS: Partial NMB with a target of T1/Tc ratio at 50% allows good recording of LSR with same outcome as surgery without NMB, and reduced spontaneous EMG activity. SIGNIFICANCE: We suggested the availability of partial NMB for intraoperative LSR monitoring.