Relationship between paraspinal muscle morphology and function in different directions in a healthy Chinese population at different ages: a cross-sectional study.

BACKGROUND: Paraspinal muscle degeneration occurs with age; however, it is unknown whether strength and endurance change with muscle cross-sectional area (CSA) and fatty infiltration (FI) parameters in Chinese healthy individuals. METHODS: A total of 94 asymptomatic Chinese volunteers were enrolled in this study. The participants were divided into three groups: young (20-39 years old, n = 27), middle-aged (40-59 years old, n = 49), and elderly (≥ 60 years old, n = 18). CSA and FI of the psoas (PS), quadratus lumborum (QL), multifidus (MF), and erector spinae (ES) were measured using magnetic resonance imaging. The Bionix Sim3 Pro was used to evaluate the maximum isometric torque and the Ito test to evaluate endurance. RESULTS: The CSA of the PS and ES in the elderly group was smaller than those in the other groups, while the CSA of QL in the young group was larger than that in the other groups. There were differences in the MF and ES FI among the three groups. The maximum isometric torque and endurance test time decreased with increasing age; however, these differences were not statistically significant. Maximum isometric torque positively correlated with the average paraspinal muscle CSA and negatively correlated with the torque and FI of the MF and ES muscles. The endurance test was found to be positively correlated with the FCSA of the MF and to be negatively correlated with the FI of the MF and ES. PS and QL can predict the maximum isometric torque, and MF and PS can predict the endurance time. CONCLUSION: MF and ES showed earlier degeneration than PS and QL. MF is the first paraspinal muscle to undergo functional area atrophy, and it plays an important role in the endurance test. The maximum moment of equal length in all directions of the lumbar spine is not completely symmetrical, but it is correlated with the imaging parameters of the paraspinal muscles. QL and PS were more activated in the lumbar activity. TRIAL REGISTRATION: The study was registered in Chinese Clinical Trial Registry and the registration number is ChiCTR2000039073 on 15/10/2020 ( https://www.chictr.org.cn/showproj.html?proj=62785 ). Ethical Approval was obtained from the Peking University Third Hospital Medical Science Research Ethics Committee (IRB00006761-M2020305).

Effects of platelet-rich plasma injection on electrical activity and biomechanics of the erector spinae muscles in lumbar myofascial pain syndrome.

Low back pain (LBP) is a highly prevalent disease. Among the various causes of LBP, one of the most frequent is myofascial pain syndrome (MPS) which affects the spinal stabilizer muscles. The aims of this study were to compare the differences in muscular electrical activity and biomechanical properties between the painful and non-painful sides in patients with unilateral MPS and to verify the feasibility of surface electromyography (sEMG) and MyotonPRO for assisting in MPS assessment. Forty patients with unilateral lumbar MPS were recruited via the Department of Rehabilitation Medicine Center of West China Hospital Sichuan University from October 2022 to October 2023. The electrical properties of the bilateral erector spinae muscles were characterized by sEMG signals during a trunk extension task. The following four time-domain features of sEMG were extracted: root mean square (RMS), mean absolute value (MAV), integrated EMG (iEMG), and waveform length (WL). And two frequency domain features were extracted: the median frequency (MDF) and mean power frequency (MPF). The mechanical properties of the muscles were assessed by MyotonPRO at rest. The following biomechanical parameters were acquired: oscillation frequency [Hz], dynamic stiffness [N/m], logarithmic decrement, relaxation time [ms], and Creep. The visual analog scale (VAS) was used to evaluate the pain severity, and the Oswestry Disability Index (ODI) was used to evaluate the severity of disability and disruption to lifestyle activities caused by LBP pain. The outcome measures were obtained prior to the Platelet-rich plasma (PRP) treatment and repeated two weeks after treatment. (1) Prior to the PRP treatment, all sEMG time-domain features on the painful side were significantly higher than those on the non-painful side (RMS, p < 0.001; MAV, p < 0.001; iEMG, p < 0.001; WL, p = 0.001). However, there was no significant difference in the sEMG frequency-domain features (MPF, p = 0.478; MDF, p = 0.758). On the mechanical side, there were significant differences in oscillation frequency (p = 0.041) and logarithmic decrement (p = 0.022) between the painful side and non-painful side, but no significant differences in dynamic stiffness, relaxation time, and creep (both p > 0.05). (2) Two weeks after the PRP treatment, statistically significant decreases were observed in both post-treatment VAS (p < 0.001) and ODI scales (p < 0.001), indicating the PRP treatment clinically significantly reduced the level of. MPS. This change coincided with all sEMG time-domain features, in which the values at the painful side decreased significantly (RMS, p = 0.001; MAV, p = 0.001; iEMG, p = 0.001; WL, p = 0.001). However, no significant difference in the sEMG frequency-domain features (MPF, p = 0.620; MDF, p = 0.850) was found. On the mechanical side, only logarithmic decrement on the painful side increased significantly (p < 0.001). Our combined MyotonPRO and sEMG results indicated that MPS likely leads to increased muscle tone and decreased muscle elasticity, manifested by abnormal time-domain features of sEMG and biomechanical properties. The changes in these objective measurements were agreed with the changes in subjective outcome measures of pain and function currently assessed in the patients with MPS. A single PRP treatment may alleviate muscle dysfunction caused by MPS. These preliminary results demonstrated the potential feasibility of using sEMG and MyotonPRO as tools for assessing the neuromuscular function of MPS.

The reliability of virtual non-contrast reconstructions of photon-counting detector CT scans in assessing abdominal organs.

BACKGROUND: Spectral imaging of photon-counting detector CT (PCD-CT) scanners allows for generating virtual non-contrast (VNC) reconstruction. By analyzing 12 abdominal organs, we aimed to test the reliability of VNC reconstructions in preserving HU values compared to real unenhanced CT images. METHODS: Our study included 34 patients with pancreatic cystic neoplasm (PCN). The VNC reconstructions were generated from unenhanced, arterial, portal, and venous phase PCD-CT scans using the Liver-VNC algorithm. The observed 11 abdominal organs were segmented by the TotalSegmentator algorithm, the PCNs were segmented manually. Average densities were extracted from unenhanced scans (HUunenhanced), postcontrast (HUpostcontrast) scans, and VNC reconstructions (HUVNC). The error was calculated as HUerror=HUVNC-HUunenhanced. Pearson's or Spearman's correlation was used to assess the association. Reproducibility was evaluated by intraclass correlation coefficients (ICC). RESULTS: Significant differences between HUunenhanced and HUVNC[unenhanced] were found in vertebrae, paraspinal muscles, liver, and spleen. HUVNC[unenhanced] showed a strong correlation with HUunenhanced in all organs except spleen (r = 0.45) and kidneys (r = 0.78 and 0.73). In all postcontrast phases, the HUVNC had strong correlations with HUunenhanced in all organs except the spleen and kidneys. The HUerror had significant correlations with HUunenhanced in the muscles and vertebrae; and with HUpostcontrast in the spleen, vertebrae, and paraspinal muscles in all postcontrast phases. All organs had at least one postcontrast VNC reconstruction that showed good-to-excellent agreement with HUunenhanced during ICC analysis except the vertebrae (ICC: 0.17), paraspinal muscles (ICC: 0.64-0.79), spleen (ICC: 0.21-0.47), and kidneys (ICC: 0.10-0.31). CONCLUSIONS: VNC reconstructions are reliable in at least one postcontrast phase for most organs, but further improvement is needed before VNC can be utilized to examine the spleen, kidneys, and vertebrae.

Effects of anterior quadratus lumborum block versus erector spinae plane block on postoperative acute pain in percutaneous nephrolithotomy: a prospective, observational study.

BACKGROUND: The study aimed to compare the pain-relieving effectiveness of anterior quadratus lumborum block (QLB3) and erector spinae plane block (ESPB), both of which have been documented to provide relief during abdominal surgery. METHODS: This prospective observational study, conducted between February and July 2023, included 96 patients who had undergone percutaneous nephrolithotomy (PCNL). Patients were divided into three groups: QLB3, ESPB, and control (no block) and received the corresponding nerve block in the preanesthetic room for regional block. Cumulative morphine consumption during the initial 24 h after PCNL, numerical rating scale resting/movement scores, intraoperative remifentanil usage, rescue analgesic requirements, time when the first analgesic was requested, and postoperative nausea and vomiting scores were documented and compared between the groups. RESULTS: Total median morphine consumption in the first 24 h postoperatively was similar in the QLB3 and ESPB groups but higher in the control group (QLB3, 7 mg [(Q1-Q3) 7-8.5]; ESPB, 8 mg [6.5-9]; control, 12.5 [10-17]; P < 0.001). Similarly, median intraoperative remifentanil consumption did not differ between the block groups but was higher in the control group (QLB3, 1082 µg [IQR 805.5-1292.7]; ESPB, 1278 µg [940.2-1297.5]; control, 1561 µg [1315-2068]; P < 0.001). The number of patients receiving rescue analgesic medication was similar in the block groups but higher in the control group (QLB3, n = 9 [30%]; ESPB, n = 14 [46.7%]; control, n = 21 [70%]; P = 0.008). CONCLUSIONS: QLB3 and ESPB were adequate and comparable in providing postoperative analgesia as part of multimodal analgesia after PCNL. TRIAL REGISTRATION: The study was registered on ClinicalTrials.gov (Identifier: NCT05822492).

Spinal stabilization exercises for transversus abdominis and lumbar multifidus thickness via telerehabilitation and face-to-face approaches in patients with nonspecific chronic neck pain: a randomized controlled trial.

Background/aim: Strengthening the muscles of the lumbar region in individuals with neck pain may be protective against future back problems. In addition, telerehabilitation applications, which gained momentum in the literature and clinical practice during the COVID-19 pandemic, are among the applications preferred by patients thanks to their various advantages. This study aimed to compare the effects of telerehabilitation and spinal stabilization exercises applied with face-to-face approaches on the thickness of the transversus abdominis (M.TrA) and lumbar multifidus (M.LM) muscles in patients with nonspecific neck pain. Materials and methods: The primary outcomes were the thickness of the M.TrA and M.LM. Neck pain intensity and neck disability were secondary outcomes. Muscle thickness was evaluated with an ultrasound device, neck pain intensity was assessed with a visual analog scale, and disability was assessed with the Neck Disability Index. Patients were randomly assigned to the telerehabilitation group (TRG) (n = 13) or the control group (CG) (n = 13). While the TRG did the exercises with live videos and video recordings, the CG did exercises face-to-face in the clinic. Both groups performed the same exercises for 45 minutes per session 3 days a week for 8 weeks. Results: At the end of the treatment, the thicknesses of the M.TrA and M.LM were increased and neck pain intensity and neck disability were decreased in both groups (p < 0.05). The groups were similar in terms of these variables (p > 0.05). Conclusion: Telerehabilitation and face-to-face spinal stabilization exercises are both beneficial for spinal muscle architecture and clinical variables as a preventive measure against future lower back problems in individuals with neck pain.

Comparison of ultrasound-guided continuous erector spinae plane block versus continuous paravertebral block for postoperative analgesia in patients undergoing proximal femur surgeries.

BACKGROUND: Proximal femur fracture surgeries have become increasingly prevalent, presenting unique challenges for postoperative pain management due to patient demographics and comorbidities. Erector spinae plane block (ESPB) has emerged as a relatively safe alternative to paravertebral block (PVB). Our aim was to compare ultrasound-guided continuous ESPB with continuous PVB for postoperative analgesia in patients undergoing proximal femur surgeries under spinal anesthesia. METHODS: A prospective randomized interventional study was conducted on 60 patients between 18 and 60 years of age undergoing proximal femur surgeries under spinal anesthesia with American Society of Anesthesiologists physical status I and II between January 2019 and April 2020. Patients were randomly assigned to receive either ultrasound-guided continuous ESPB (Group E, n = 30) or ultrasound-guided continuous PVB (Group P, n = 30) using a computer-generated randomization table. The mean maximum visual analog scale (VAS) score, VAS score in the first 24 h, the time of rescue analgesia, and total requirement of rescue analgesia were assessed. RESULTS: The maximum VAS score within the first 24 h was numerically higher in Group P but statistically insignificant (p-value 0.279). VAS scores at 0, 1, 2, 6, and 18 h postoperatively were comparable in both groups. However, at the 24-h mark, the VAS score between Group E and Group P was statistically significant (p-value 0.018) but not clinically relevant. The mean paracetamol and tramadol requirements were comparable between the two groups. CONCLUSION: Continuous ESPB is as effective as continuous PVB for postoperative analgesia in proximal femur surgeries. The enhanced safety profile of erector spinae block underscores its significance in postoperative pain management.

Effects of a Manual Treatment on Lumbar Microcirculation and Tissue Stiffness Following Submaximal Eccentric Trunk Extensor Exercise: A Randomized Controlled Trial.

Recent studies have shown that the extramuscular connective tissue (ECT) is thickened and stiffened in delayed onset muscle soreness (DOMS). However, contrarily to the normal population, severe DOMS is rare in athletes or highly trained individuals. The present randomized, controlled trial therefore aimed to investigate pain as well as microcirculation and stiffness of the ECT and the erector spinae muscle following submaximal eccentric trunk extension exercise not causing DOMS. The effect of manual treatment by a therapist (myofascial release; MFR) on these parameters was to be studied. Trained healthy participants (n = 21; 31.3 ± 9.6 years; > 4 h exercise per week) performed submaximal eccentric exercise of the trunk extensors. One group was manually treated (n = 11), while the other group (n = 10) received placebo treatment with sham laser therapy. Stiffness of the ECT and the erector spinae muscle (shear wave elastography), microcirculation (white light and laser Doppler spectroscopy), palpation pain (100 mm visual analogue scale, VAS) and pressure pain threshold (indentometry, PPT) were assessed before (t0), 24 h (t24) and 48 h (t48) after conditions. Erector spinae muscle stiffness increased after eccentric exercise from t0 to t24 (0.875 m/s) and from t0 to t48 (0.869 m/s). After MFR, erector spinae muscle stiffness decreased in contrast to placebo treatment at t24 (-0.66 m/s), while ECT stiffness remained unchanged. Oxygen saturation increased (17-20.93%) and relative haemoglobin decreased (-9.1 - -12.76 AU) after eccentric exercise and MFR differed from placebo treatment at t48 (-3.71 AU). PPT differed after MFR from placebo treatment at t48 (20.69 N/mm), while VAS remained unchanged. Multiple linear regression showed that ECT stiffness and group membership predicted erector spinae muscle stiffness. MFR could have a positive effect on pain, microcirculation and muscle stiffness after submaximal eccentric exercise, suggesting better recovery, which needs to be confirmed by future work.

[Application of Erector Spinae Plane Block in Spine Surgery:A Review].

Spine surgery may lead to moderate to severe pain.Poorly controlled postoperative pain seriously affects the prognosis and recovery of patients.The erector spinae plane block (ESPB),firstly proposed in 2016 as a novel interfascial plane block,has been widely used in the management of intraoperative and postoperative pain in spine surgery.It has been confirmed as a safe,simple,and effective block.This review describes the anatomic basis,mechanism,and methods of ESPB,summarizes the clinical application of ESPB in spine surgery,and makes an outlook on the potential role of ESPB as a part in the multimodal management of postoperative pain in spine surgery.

MRI-based assessment paraspinal extensor muscle fatty infiltration in acute cervical spinal cord injury patients - a retrospective study.

BACKGROUND: The effect of fat infiltration in the paraspinal muscles on cervical degenerative disease has been confirmed by multiple studies. However, little is known about fat infiltration in the paraspinal extensors in patients with acute cervical spinal cord injury (SCI). This study aimed to investigate the difference in paraspinal extensor fatty infiltration between patients with acute cervical SCI and healthy controls, and to further explore the protective role of the paravertebral extensor muscles in patients with cervical SCI. METHODS: A total of 50 patients with acute cervical SCI admitted to the emergency department from January 2019 to November 2023 were retrospectively analyzed, including 26 males and 24 females, with an average age of 59.60 ± 10.81 years. A control group of 50 healthy middle-aged and elderly individuals was also included, comprising 28 males and 22 females, with an average age of 55.00 ± 8.21 years. Cervical spine magnetic resonance imaging (MRI) was used to measure the cross-sectional areas of the superficial and deep cervical extensor muscles, the corresponding vertebral body cross-sectional areas, and the fat area within the superficial and deep extensor muscle groups using Image J software. Differences between the two groups were compared, and the cervical SCI patients were further analyzed based on the severity of the spinal cord injury and gender differences. RESULTS: The deep fatty infiltration ratio (DFIR) and superficial fatty infiltration ratio (SFIR) at C4-C7 in the cervical SCI group were significantly higher than those in the control group (P < 0.001). The cross-sectional area of the functional deep extensor area (FDEA) relative to the vertebral body area (VBA) and the cross-sectional area of the functional superficial extensor area (FSEA) relative to the VBA at the C5 and C6 levels in the cervical SCI group were significantly lower than those in the control group (P < 0.001, P < 0.001, P = 0.034, P = 0.004 respectively). Among the cervical SCI patients, the cross-sectional areas of the deep extensor area (DEA) and the superficial extensor area (SEA) in males were significantly higher than those in females (P < 0.001). At the C6 and C7 levels, the FDEA/VBA and FSEA/VBA ratios in the male group were higher than those in the female group (P = 0.009, P = 0.022, P = 0.019, P = 0.005, respectively). CONCLUSION: Patients with acute cervical SCI exhibit significantly higher fatty infiltration and a greater degree of paravertebral extensor muscle degeneration compared to healthy controls. This finding underscores the importance of the paravertebral extensor muscles in the context of cervical SCI and may guide future therapeutic strategies.

AB041. The morphological changes of paraspinal muscles in adult brachial plexus injury.

BACKGROUND: Traumatic brachial plexus injury (BPI) is a debilitating injury that has a devastating impact. However, management of BPI remains a complex challenge, not only in diagnosis but also in treatment strategies for reconstructive microsurgeons. The aim of this study was to develop an additional assessment tool for root avulsion based on the volume of paraspinal muscle (PM) prior to surgical intervention, making the preoperative diagnosis more precise. METHODS: This retrospective study was centered on adult patients with BPI who underwent surgical exploration and treatment, postoperative follow-up at the Chang Gung Hospital. Labeling of PMs was aided by semi-automated segmentation using 3D Slicer 5.2.2. Slices spanning from the lower end of the upper vertebral body endplate to the upper end of the lower vertebral body. The ratio of muscle volume on the lesion side to that on the normal side (L/N ratio), indicating the volume proportion between the injured and healthy areas, serves as the primary parameter for assessing the relationship in root avulsion. RESULTS: The L/N ratio for the deepest layers of PMs consistently predicted the level of root injury across C4 to C7 levels, with all reaching statistical significance. In terms of partial and total root avulsion, the L/N ratio of layer 4th at 0.78 significantly outperforms other methods. Concerning the timing of MRI, both partial avulsion (PA) and total avulsion (TA) groups of merge roots showed a statistically significant decrease in the L/N ratio over time. CONCLUSIONS: In conclusion, the L/N volume ratio of 4th layer in PMs reliably predicts the functional severity of avulsed roots and surpasses the performance of traditional diagnostic tools under specific conditions.

Spine muscle auto segmentation techniques in MRI imaging: a systematic review.

BACKGROUND: The accurate segmentation of spine muscles plays a crucial role in analyzing musculoskeletal disorders and designing effective rehabilitation strategies. Various imaging techniques such as MRI have been utilized to acquire muscle images, but the segmentation process remains complex and challenging due to the inherent complexity and variability of muscle structures. In this systematic review, we investigate and evaluate methods for automatic segmentation of spinal muscles. METHODS: Data for this study were obtained from PubMed/MEDLINE databases, employing a search methodology that includes the terms 'Segmentation spine muscle' within the title, abstract, and keywords to ensure a comprehensive and systematic compilation of relevant studies. Systematic reviews were not included in the study. RESULTS: Out of 369 related studies, we focused on 12 specific studies. All studies focused on segmentation of spine muscle use MRI, in this systematic review subjects such as healthy volunteers, back pain patients, ASD patient were included. MRI imaging was performed on devices from several manufacturers, including Siemens, GE. The study included automatic segmentation using AI, segmentation using PDFF, and segmentation using ROI. CONCLUSION: Despite advancements in spine muscle segmentation techniques, challenges still exist. The accuracy and precision of segmentation algorithms need to be improved to accurately delineate the different muscle structures in the spine. Robustness to variations in image quality, artifacts, and patient-specific characteristics is crucial for reliable segmentation results. Additionally, the availability of annotated datasets for training and validation purposes is essential for the development and evaluation of new segmentation algorithms. Future research should focus on addressing these challenges and developing more robust and accurate spine muscle segmentation techniques to enhance clinical assessment and treatment planning for musculoskeletal disorders.

Development and validation of metrics for assessment of ultrasound-guided fascial block skills☆.

BACKGROUND: As few anaesthetists provide lumbar erector spinae block for disc surgery, there is a need to provide training to enable a randomised controlled trial investigating analgesia after painful spinal surgery (NIHR153170). The primary objective of the study was to develop and measure the construct validity of a checklist for assessment of skills in performing lumbar and thoracic erector spinae fascial plane injection using soft-embalmed Thiel cadavers. METHODS: Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphi questionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter, we validated the checklist by comparing the performance of 12 experts with 12 novices, each performing lumbar and thoracic erector spinae plane injections or fascia iliaca, serrato-pectoral (PEC II) and serratus injections, randomly allocated to the left and right sides of six soft-embalmed Thiel cadavers. Six expert, trained raters blinded to operator and site of block examined 120 videos each. RESULTS: The mean (95% confidence interval) internal consistency of the 11-item checklist for erector spinae plane injection was 0.72 (0.63-0.79) and interclass correlation was 0.88 (0.82-0.93). The checklist showed construct validity for lumbar and thoracic erector spinae injection, experts vs novices {median (interquartile range [range]) 8.0 (7.0-10.0 [1-11]) vs 7.0 (5.0-9.0 [4-11]), difference 1.5 (1.0-2.5), P<0.001}. Global rating scales showed construct validity for lumbar and thoracic erector spinae injection, 28.0 (24.0-31.0 [7-35]) vs 21.0 (17.0-24.0 [7-35]), difference 7.5 (6.0-8.5), P<0.001. The most difficult items to perform were identifying the needle tip before advancing and always visualising the needle tip. Instrument handling and flow of procedure were the areas of greatest difficulty on the global rating scale (GRS). Checklists and GRS scores correlated. There was homogeneity of regression slopes controlling for status, type of injection, and rater. Generalisability analysis showed a high reliability using the checklist and GRS for all fascial plane blocks (Rho [ρ2] 0.93-0.96: Phi [ϕ] 0.84-0.87). CONCLUSIONS: An 11-point checklist developed through a modified Delphi process to provide best practice guidance for fascial plane injection showed construct validity in performing lumbar and thoracic erector spinae fascial plane injection in soft-embalmed Thiel cadavers.

Analgesic efficacy and safety of erector spinae plane block in pediatric patients undergoing elective surgery: A systematic review and Meta-analysis of randomized controlled trials.

STUDY OBJECTIVE: Ultrasound-guided erector spinae plane block (ESPB) is commonly used for perioperative analgesia in adults; however, its analgesic efficacy and safety in pediatric patients remain uncertain. This review aimed to determine whether ultrasound-guided ESPB can improve analgesic efficacy and safety in pediatric surgery. DESIGN: Meta-analysis of randomized controlled trials. SETTING: Perioperative setting. PATIENTS: Pediatric patients undergoing elective surgery under general anesthesia. INTERVENTIONS: We searched PubMed, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, KoreaMed, Web of Science, Scopus, and ClinicalTrials.gov databases for eligible published randomized controlled studies (RCTs) comparing ESPB with controls (no block or other block) in pediatric patients undergoing elective surgery under general anesthesia. MEASUREMENTS: The primary outcome was cumulative opioid consumption after surgery. Other outcomes included intraoperative opioid consumption, time to first request for rescue analgesia, number of patients requiring rescue analgesics, and pain scores after surgery. The safety outcomes were the incidences of bradycardia, hypotension, and postoperative vomiting. MAIN RESULTS: The analysis included 17 RCTs comprising 919 participants: 461 in the ESPB group, 269 in the no-block group (no block/sham block), and 189 in the other block group. Compared with the control group (no block and other blocks), ESPB significantly reduced the cumulative opioid consumption (intravenous morphine milligram equivalents) after surgery (standardized mean difference = -1.51; 95% confidence interval, -2.39 to -0.64; P = 0.0002; I2 = 92.9%) and intraoperative opioid consumption, and lowered average pain scores up to 24 h after surgery. ESPB extended the time to the first request for rescue analgesia and decreased the number of patients requiring rescue analgesics. Furthermore, ESPB lowered the pain score at most time points for 24 h after surgery, improved parental satisfaction, and reduced the incidence of postoperative vomiting compared with that in no block/sham block. CONCLUSIONS: ESPB provides effective and safe perioperative analgesia in pediatric patients undergoing elective surgery under general anesthesia.

Thoracic sarcopenia measured by Hounsfield unit average calculation predicts morbidity and mortality in coronary artery bypass grafting.

OBJECTIVES: The aim of the study was to investigate the potential prognostic role of preoperative measurement of erector spinae myosteatosis with Hounsfield unit average calculation as a marker for sarcopenia and frailty in patients undergoing coronary bypass surgery. METHODS: Preoperative computer tomography-derived measurements of 479 consecutive patients undergoing coronary bypass surgery between January 2017 and December 2019 were retrospectively performed. The erector spinae muscle at the level of the 12th vertebra was manually outlined bilaterally on the axial computer tomography slices and Hounsfield unit average calculation was performed. The lower quartile of muscle density values was defined as myosteatotic and thus sarcopenic. Sarcopenic (n = 121) versus non-sarcopenic patients (n = 358) were compared regarding postoperative morbidity and short- and long-term mortality. Results were adjusted for age, body mass index, atrial fibrillation and hypertension using inverse probability weighting. RESULTS: Sarcopenia was associated with higher 30-day mortality (4.1% vs 0.8%; P = 0.012), mid-term mortality after 1 year (9.3% vs 3.1%; P = 0.047) and 2 years (10.8% vs 4.2%; P = 0.047). Long-term mortality (5 years) was 20.8% for sarcopenic and 13.0% for non-sarcopenic patients but was not found to be significantly different (P = 0.089). Sarcopenia was associated with higher rates of reintubation (7.5% vs 1.1%; P < 0.001), sternal wound infections (7.5% vs 2.8%; P = 0.039) and acute kidney injury requiring haemodialysis (2.5% vs 0.4%; P = 0.021). CONCLUSIONS: In patients undergoing coronary bypass surgery, sarcopenia was associated with increased short-term mortality, mid-term mortality and morbidity. The measurement of erector spinae myosteatosis could be an easy and useful parameter in preoperative risk assessment.

Effects of hand dominance on myoelectric signal of non­fatigued lumbar multifidus muscle during single arm lifts.

Some evidence indicates that lower back muscles located at the non­dominant side of the body are more fatigue resistant than their opposite counterparts presumably due to preferential use of the dominant hand. The aim of the study was to determine if any distinction exists in the surface electromyographic activity of corresponding contralateral non­fatigued lumbar multifidus (LM) muscles as a function of hand dominance. The relative to maximum root mean square, the median frequency (MdF) and spike shape parameters were computed from the surface myoelectric signals of ipsilateral and contralateral lumbar multifidus muscle of 46 adult healthy subjects (27 right­handed, 19 left­handed) during voluntary contractions evoked by the single arm lifts in prone position. Activation of LM as a contralateral muscle to lifted arm was greater than as ipsilateral muscle, independently of handedness. Regardless if LM performed ipsi­ or contralateral action to the lifted arm, the mean spike amplitude, slope, number of peaks per spike and spike duration were greater and mean spike frequency as well as MdF were smaller in the muscle of dominant than non­dominant side. Combined changes of spike shape measures indicate increased recruitment, lower firing rates and higher synchronization of motor units in the LM of dominant side as compared to its counterpart.