Complications and Technical Consideration of Ultrasound-Guided Rectus Sheath Blocks: A Retrospective Analysis of 4033 Patients.

BACKGROUND: Although the ultrasound-guided rectus sheath block (RSB) is usually regarded as an easy and safe procedure in clinical settings, there is currently no report on complications incidence. Therefore, the present study investigated complications in a large cohort and described the technical considerations to minimize complications of real-time ultrasound-guided RSBs. METHODS: This was a retrospective cohort study of patients who underwent real-time ultrasound-guided RSBs for perioperative pain control in laparoscopic surgery with an umbilical port between February 1, 2017, and February 28, 2021, at the Asan Medical Center in South Korea. All RSBs were performed bilaterally using a 23-gauge Quincke needle, and a bilateral 2-block placement was regarded as 1 RSB. Patient data, including demographics, preoperative laboratory data, preoperative antiplatelet or anticoagulant medication with the duration of discontinuation, and type of surgery, were collected to show the study population characteristics and explore potential factors associated with adverse events such as hematoma. Ultrasound images of patients and adverse events of RSBs, including extrarectus sheath injections, vascular injuries, bowel injury, or local anesthetic systemic toxicity, were also analyzed accordingly. RESULTS: A total of 4033 procedures were analyzed. The mean body mass index of the patients was 24.1 (21.8-26.5) kg/m2. The preoperative laboratory data were within normal range in 4028 (99.9%) patients. Preoperative antiplatelets or anticoagulants were administered in 17.3% of the patients. Overall, 96 complications (2.4%) were observed. Among them, extrarectus sheath injection occurred in 88 cases (2.2%), which included preperitoneal injection (0.9%) and intraperitoneal injection (1.3%). Vascular injuries constituted 8 cases (0.2%) and all vascular injuries resulted in hematoma: 7 cases of inferior epigastric artery injury with rectus sheath hematoma and 1 of inferior mesenteric artery injury with retroperitoneal hematoma. Bowel injury or local anesthetic systemic toxicity was not reported. CONCLUSIONS: In this study of RSBs performed on 4033 patients using a 23-gauge Quincke needle in patients with low body mass index, there were 8 cases (0.2%) of vascular injury, all of which accompanied hematoma.

Preemptive visceral analgesic effect of thoracic paravertebral block on postoperative opioid consumption in patients undergoing laparoscopic cholecystectomy: a prospective, randomized, assessor-blind study.

BACKGROUND: The preemptive visceral analgesic effect of regional nerve block has not been adequately investigated to date. We evaluated the preemptive visceral analgesic effect of thoracic paravertebral block (TPVB) in patients undergoing laparoscopic cholecystectomy (LC) in whom pre-incisional rectus sheath block (RSB) was used to minimize somatic surgical pain. METHODS: In this prospective, randomized, assessor-blind study, 70 patients scheduled for elective LC were randomly assigned to the pre-TPVB (n = 35) or the post-TPVB (n = 35) group. Both groups received pre-incisional RSB, and patients in the pre-TPVB group received TPVB before skin incision while those in the post-TPVB group received TPVB after skin closure. The primary outcome was the total rescue analgesic consumption (morphine equianalgesic dose) during the 24 h post-surgery. The secondary outcomes were the cumulative analgesic consumption and pain intensity for 24 h after surgery, and adverse events. RESULTS: Pre-TPVB significantly reduced total rescue analgesic consumption (estimated mean [95% CI]) during the 24 h after surgery than post-TPVB (16.9 [14.5, 19.3] vs. 25.3 [22.8, 27.7] mg, estimated difference: -8.3 [-11.8, -4.9], P < 0.001). The cumulative rescue analgesic consumption was significantly lower in the pre-TPVB group from 2-24 h after surgery (P < 0.001). The postoperative pain intensity was significantly lower in the pre-TPVB group as well at 0.5-6 h after surgery. There were no adverse events in both groups. CONCLUSIONS: Pre-incisional TPVB conferred a significant preemptive visceral analgesic effect in patients undergoing LC, and significantly reduced the amount of postoperative opioid consumption.

Effectiveness of percutaneous epidural neuroplasty using a balloon catheter in patients with chronic spinal stenosis accompanying mild spondylolisthesis: a longitudinal cohort study.

Background: Degenerative lumbar spondylolisthesis (DLS) is frequently associated with lumbar spinal stenosis (LSS) and conservative treatments such as epidural steroid injection do not have long-term benefits in LSS patients with DLS. This study evaluated the effectiveness of percutaneous epidural neuroplasty using a balloon catheter in patients with LSS and DLS. Methods: Patients' sex, age, body mass index, diabetes, hypertension, stenosis grading, pain duration, location, pain intensity, and medications were retrieved from electronic medical records. At 1, 3, and 6 months following the procedure, data on pain severity, medication usage, and physical functional status were analyzed. A generalized estimating equations model was used at the six-month follow-up. Patients were divided into those with DLS (the spondylolisthesis group) and those without DLS (the no spondylolisthesis group) to evaluate whether the effects of percutaneous epidural neuroplasty using a balloon catheter were different. Results: A total of 826 patients were included (spondylolisthesis: 433 patients, 52.4%; no spondylolisthesis: 393 patients, 47.6%). Age, body mass index, hypertension, pain location, and stenosis grading were statistically different between the two groups. The generalized estimating equations analyses with unadjusted and adjusted estimation revealed a significant improvement in the estimated mean numerical rating scale of pain intensities compared to that at baseline in both groups (P < 0.001). Any adverse events that occurred were minor and temporary. Conclusions: Percutaneous epidural neuroplasty using a balloon catheter may be an alternative treatment option for patients with chronic LSS, regardless of accompanying DLS, who have had failed conservative management.

Effectiveness of Epidural Balloon Neuroplasty in Patients With Chronic Spinal Stenosis Accompanied by Redundant Nerve Roots: A Longitudinal Cohort Study.

BACKGROUND: Symptomatic patients with chronic lumbar spinal stenosis (LSS) accompanied by redundant nerve roots (RNR) have poor treatment outcomes. Recently, epidural balloon neuroplasty has been shown to be effective in patients with chronic LSS. OBJECTIVE: To evaluate the effectiveness of epidural balloon neuroplasty in patients with chronic LSS accompanied by RNR. STUDY DESIGN: Retrospective cohort study. SETTING: A single pain clinic of a tertiary medical center in Seoul, Republic of Korea. METHODS: Patients with chronic LSS were divided into groups with (RNR group) and without RNR (non-RNR group). The generalized estimating equations (GEE) model was used to evaluate the effectiveness of epidural balloon neuroplasty in both groups based on Numeric Rating Scale (NRS-11) score for pain intensity, Medication Quantification Scale III (MQS III), and proportion of functional improvement at one, 3, and 6 months postprocedure. RESULTS: GEE analyses showed a significant reduction of pain intensity in NRS-11 and functional improvement compared to baseline throughout the 6-month follow-up period in both groups (P < 0.001), without differences between groups. After adjusting for potential confounding variables, the NRS-11 of leg pain one month after the procedure in the RNR group was reduced less than that in the non-RNR group (P = 0.016), although we did not find a significant time and group interaction. After adjustment, less functional improvement was observed 3 months after the procedures in the RNR group than in the non-RNR group (P = 0.001), with a significant interaction between time and group (P = 0.003). The estimated mean MQS III values were unchanged at 6 months regardless of adjustment in both groups. LIMITATIONS: Retrospective design and a lack of information on adjuvant nonpharmacologic therapies. CONCLUSION: Epidural balloon neuroplasty may be an effective option for reducing pain in patients with chronic LSS accompanied by RNR.

A Water-Soluble Organic Photocatalyst Discovered for Highly Efficient Additive-Free Visible-Light-Driven Grafting of Polymers from Proteins at Ambient and Aqueous Environments.

Since the pioneering discovery of a protein bound to poly(ethylene glycol), the utility of protein-polymer conjugates (PPCs) is rapidly expanding to currently emerging applications. Photoinduced energy/electron-transfer reversible addition-fragmentation chain-transfer (PET-RAFT) polymerization is a very promising method to prepare structurally well-defined PPCs, as it eliminates high-cost and time-consuming deoxygenation processes due to its oxygen tolerance. However, the oxygen-tolerance behavior of PET-RAFT polymerization is not well-investigated in aqueous environments, and thereby the preparation of PPCs using PET-RAFT polymerization needs a substantial amount of sacrificial reducing agents or inert-gas purging processes. Herein a novel water-soluble and biocompatible organic photocatalyst (PC) is reported, which enables visible-light-driven additive-free "grafting-from" polymerizations of a protein in ambient and aqueous environments. Interestingly, the developed PC shows unconventional "oxygen-acceleration" behavior for a variety of acrylic and acrylamide monomers in aqueous conditions without any additives, which are apparently distinct from previously reported systems. With such a PC, "grafting-from" polymerizations are successfully performed from protein in ambient buffer conditions under green light-emitting diode (LED) irradiation, which result in various PPCs that have neutral, anionic, cationic, and zwitterionic polyacrylates, and polyacrylamides. It is believed that this PC will be widely employed for a variety of photocatalysis processes in aqueous environments, including the living cell system.

Analysis of perioperative cardiac arrest in a rural hospital in Korea.

BACKGROUND: Perioperative cardiac arrest has been studied in many countries but few related studies have been conducted in Korea. Previous studies were not applicable to rural hospitals due to differences in the demographics between the regions. In the present study, the incidence, mortality, and related factors of perioperative cardiac arrest in a hospital in Youngdong province were analyzed and compared with previous research. METHODS: A retrospective study was conducted from the January 1, 2012, to December 31, 2018, on patients who underwent both anesthesia and surgery in our hospital. Patients who received local anesthesia were not included in the study. The collected data included the patient characteristics, anesthesia methods, the American Society of Anesthesiologists physical status, surgical department, emergency status, traumatic status, pre- and post-cardiac arrest medical records, and patient outcomes. RESULTS: A total of 57,746 patients received anesthesia and underwent surgery during the study period, and 28 patients (4.85 per 10,000 anesthesia cases) received cardiopulmonary cerebral resuscitation (CPCR) during or within 24 h of surgery. Eight patients survived and twenty patients died (3.46 per 10,000 anesthesia cases). There were three anesthesia-related arrests and all of these patients survived. When limiting the analysis to patients with intraoperative CPCR, the incidence and mortality were 1.56, and 1.39 per 10,000 anesthesia cases, respectively. CONCLUSIONS: The incidence and mortality of perioperative cardiac arrest in our hospital were higher than those in a recent study in Seoul, demonstrating a regional gap in Korea.

Transversus abdominis plane block as a sole anesthetic technique for evacuation of rectus abdominis muscle hematoma - A case report.

BACKGROUND: Transversus abdominis plane (TAP) blocks have been used for analgesia in various abdominal surgeries. However, a TAP block as the sole anesthetic method for surgery has rarely been reported. CASE: A 33-year-old breastfeeding primipara woman was admitted to the hospital due to a rectus abdominis muscle hematoma. Because the patient refused other anesthetic methods, evacuation of the hematoma was performed under an ultrasound-guided bilateral TAP block. A 23-gauge needle was inserted in an in-plane method using a linear ultrasound probe. An injection of 10 ml of 2% lidocaine was made to the right lateral TAP and the left lateral TAP. After confirming the sensory blockade of the T10 to T12 dermatomes, surgery was performed successfully. The patient's condition stabilized during the surgery. Breastfeeding was performed on the day of surgery. CONCLUSIONS: The evacuation of an abdominal wall hematoma in a breastfeeding patient was successfully performed under a bilateral TAP block.

Serratus anterior plane block combined with monitored anesthesia care for surgery of lateral side of breast -a case report.

BACKGROUND: In breast surgery, regional anesthesia rather than primary anesthesia has been mainly used for postoperative analgesia. Serratus anterior plane block is a new method for ultrasound-guided thoracic wall block. It is less invasive and relatively safer than conventional regional anesthetic techniques. CASE: We report a case of breast surgery under serratus anterior plane block as primary anesthesia with monitored anesthesia for a 78-year-old patient with a medical history of cardiopulmonary resuscitation due to stress-induced cardiomyopathy caused by pneumonia. CONCLUSIONS: Serratus anterior plane block might be simple and effective technique for breast surgery when a lesion is located on lateral side.