M-mode Ultrasonography Research Articles

292 - Quantification of pelvic floor function using M-mode ultrasonography for patients with urinary incontinence after radical prostatectomy, changes in pelvic floor function due to pelvic floor muscle training guidance, and elucidation of the relationship between the degree of urinary incontinence and pelvic floor function

292 - Quantification of pelvic floor function using M-mode ultrasonography for patients with urinary incontinence after radical prostatectomy, changes in pelvic floor function due to pelvic floor muscle training guidance, and elucidation of the relationship between the degree of urinary incontinence and pelvic floor function

B-flow/spatiotemporal image correlation M-mode ultrasound provides novel method to quantify spiral artery remodeling during normal human pregnancy.

During human pregnancy, placental extravillous trophoblasts replace vascular smooth muscle and elastic tissue within the walls of the uterine spiral arteries, thereby remodeling them into distensible low-resistance vessels to promote placental perfusion. The present study determined whether B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography provides an in-vivo imaging method able to digitally quantify spiral artery luminal distensibility as a physiological index of spiral artery remodeling during the advancing stages of normal human pregnancy. A prospective, longitudinal, observational study was conducted to quantify spiral artery distensibility (i.e. vessel luminal diameter at systole minus diameter at diastole) by B-flow/STIC M-mode ultrasonography during the first, second and third trimesters in 290 women exhibiting a normal pregnancy. Maternal serum levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1), growth factors that modulate important events in spiral artery remodeling, were quantified in a subset of the women in the first, second and third trimesters of pregnancy. Median (interquartile range (IQR)) spiral artery distensibility increased progressively between the first (0.17 (0.14-0.21) cm), second (0.23 (0.18-0.28) cm) and third (0.26 (0.21-0.35) cm) trimesters of pregnancy (P < 0.0001 for all). Median (IQR) spiral artery volume flow increased progressively between the first (2.49 (1.38-4.99) mL/cardiac cycle), second (3.86 (2.06-6.91) mL/cardiac cycle) and third (7.79 (3.83-14.98) mL/cardiac cycle) trimesters (P < 0.001 for all). In accordance with the elevation in spiral artery distensibility, the median (IQR) ratio of serum PlGF/sFlt-1 × 103 levels increased between the first (7.2 (4.5-10.0)), second (22.7 (18.6-42.2)) and third (56.2 (41.9-92.5)) trimesters (P < 0.001 for all). The present study shows that B-flow/STIC M-mode ultrasonography provides an in-vivo imaging technology to quantify digitally the structural and physiological expansion of the walls of the spiral arteries during the cardiac cycle as a consequence of their transformation into compliant vessels during advancing stages of normal human pregnancy. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Assessment of Lateral Abdominal Muscle Activation Asymmetry via M-mode Ultrasonography.

This study aimed to evaluate the asymmetry in the lateral abdominal muscles (LAMs) expressed as tissue deformation index asymmetry (aTDI) with the use of M-mode ultrasonography. The muscles of interest were the transversus abdominis, internal oblique, and external oblique. This is a cohort of 126 healthy subjects who participated in the study. Measurements were taken by two raters, blinded to the aim of the study. M-mode ultrasounds with a measurement frequency of 5 MHz were utilized to record the postural response of LAMs to external perturbation in the form of rapid arm abduction with load, and individual aTDI values for each muscle were calculated. The aTDI values from deep to superficial LAMs were 78.28% for transversus abdominis, 55.68% for internal oblique, and 44.80% for external oblique. Only the aTDI for transversus abdominis results differed significantly from those of the other LAMs (P<0.05). LAM asymmetry values exhibit the following gradient: transversus abdominis >internal oblique >external oblique. Specifically, only transversus abdominis demonstrates noteworthy asymmetry in postural activity. This observation contributes to the literature by indicating that transversus abdominis asymmetry may serve as a marker for assessing the variability in motor control of the deep abdominal musculature. The dominance of transversus abdominis (TrA) asymmetric activity underlines the importance of personalized approaches for patients with lumbopelvic disorders or for athletes seeking to enhance performance.

Incidence of Hemidiaphragmatic Paralysis After Ultrasound Guided Low Dose Interscalene Brachial Plexus Block

Background and Aims: Hemidiaphragmatic paralysis is a complication of single shot and continuous interscalene brachial plexus block that can be minimised by ultrasound guided extra fascial catheter placements and by limiting the amount of local anaesthetic administered. In this study, we report incidence of hemidiaphragmatic paralysis with patient-controlled infusion of low volume of ropivacaine after ultrasound guided low dose interscalene brachial plexus block (LD-ISB). Methods: Patients aged 18-65 years undergoing surgery for shoulder dislocation or proximal humerus fracture were recruited and administered general anaesthesia. Before extubation ultrasound guided LD-ISB (10 ml of 0.5% ropivacaine) was administered and a catheter tunneled so that patient controlled interscalene analgesia (PCIA) could be given with low volume ropivacaine. PCIA was initiated after four hours in the post operative recovery to deliver background infusion of 2 ml/h, bolus of 5ml (0.2% of ropivacaine) with lockout interval of 30 minutes for a total duration of 24 hours. Incidence of hemidiaphragmatic paralysis was recorded at extubation using M-mode ultrasonography. Before start of PCIA i.e. at 4 hours and after start of PCIA i.e. 6,12 and 24 h after extubation. Results: PCIA after LD-ISB was administered to 29 patients. Subsequently, two patients were excluded due to catheter dislodgement. The incidence of complete and partial paresis of diaphragm after extubation was 85% and 3.7% with LD-ISB respectively but was resolved before start of PCIA i.e., at 4 hours. Thus, at time of commencement of PCIA all patients had normal diaphragmatic excursions and subsequently at 6,12 and 24 h no paresis/paralysis was reported in patients administered only the background infusion or an additional single bolus dose of ropivacaine with the background infusion. Partial paresis was noted in all patients in which two bolus doses/h were administered. All patients with paresis had diaphragmatic excursion normalised in the next recording made at 4 hours and no complication was reported in any patient. VAS (Visual Analog Scale) was below 3 at all time points. Conclusion: Partial/complete paresis after a single shot injection of 10 ml of 0.5% ropivacaine resolves in 4 hours. PCIA initiated after it for subsequent 20 hours with a single bolus dose of 5ml of 0.2% ropivacaine and background infusion at 2 ml/h does not cause phrenic paresis. Partial paresis is reported with two bolus doses/h, but it is clinically asymptomatic. Thus, the above dose regimes are safe and effective in managing post-operative pain. Keywords: Interscalene block, Diaphragmatic paresis, Ropivacaine, continuous infusion, Analgesic efficacy

Transoral M-mode ultrasonography to detect tongue fasciculation in patients with amyotrophic lateral sclerosis

Transoral M-mode ultrasonography to detect tongue fasciculation in patients with amyotrophic lateral sclerosis

Quantitative assessment of pneumothorax by using Shannon entropy of lung ultrasound M-mode image and diaphragmatic excursion based on automated measurement.

Lung ultrasound (LUS) and diaphragm ultrasound (DUS) are the appropriate modalities for conservative observation to those patients who are with stable pneumothorax, as well as for the timely detection of life-threatening pneumothorax at any location, due to they are portable, real-time, relatively cost effective, and most important, without radiation exposure. The absence of lung sliding on LUS M-mode images and the abnormality of diaphragmatic excursion (DE) on DUS M-mode images are the most common and novel diagnostic criteria for pneumothorax, respectively. However, visual inspection of M-mode images remains subjective and quantitative analysis of LUS and DUS M-mode images are required. Shannon entropy of LUS M-mode image (ShanEnLM) and DE based on the automated measurement (DEAM) are adapted to the objective pneumothorax diagnoses and the severity quantifications in this study. Mild, moderate, and severe pneumothoraces were induced in 24 male New Zealand rabbits through insufflation of room air (5, 10 and 15, and 25 and 40 mL/kg, respectively) into their pleural cavities. In vivo intercostal LUS and subcostal DUS M-mode images were acquired using a point-of-care system for estimating ShanEnLM and DEAM. ShanEnLM and DEAM as functions of air insufflation volumes exhibited U-shaped curves and were exponentially decreasing, respectively. Either ShanEnLM or DEAM had areas under the receiver operating characteristic curves [95% confidence interval (CI)] of 1.0000 (95% CI: 1.0000-1.0000), 0.9833 (95% CI: 0.9214-1.0000), and 0.9407 (95% CI: 0.8511-1.0000) for differentiating between normal and mild pneumothorax, mild and moderate pneumothoraces, and moderate and severe pneumothoraces, respectively. Our findings imply that the combination of ShanEnLM and DEAM give the promising potential for pneumothorax quantitative diagnosis.

Reliability and validity of ultrasonography in evaluating the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals: a systematic review

ObjectiveTo summarize the reliability and validity of ultrasonography in evaluating the stiffness, excursion, stiffness, or strain rate of diaphragm, intercostals and abdominal muscles in healthy or non-hospitalized individuals.Literature searchPubMed, Embase, SPORTDiscus, CINAHL and Cochrane Library were searched from inception to May 30, 2022.Study selection criteriaCase–control, cross-sectional, and longitudinal studies were included if they investigated the reliability or validity of various ultrasonography technologies (e.g., brightness-mode, motion-mode, shear wave elastography) in measuring the thickness, excursion, stiffness, or strain rate of any respiratory muscles.Data synthesisRelevant data were summarized based on healthy and different patient populations. The methodological quality by different checklist depending on study design. The quality of evidence of each psychometric property was graded by the Grading of Recommendations, Assessment, Development and Evaluations, respectively.ResultsThis review included 24 studies with 787 healthy or non-hospitalized individuals (e.g., lower back pain (LBP), adolescent idiopathic scoliosis (AIS), and chronic obstructive pulmonary disease (COPD)). Both inspiratory (diaphragm and intercostal muscles) and expiratory muscles (abdominal muscles) were investigated. Moderate-quality evidence supported sufficient (intra-class correlation coefficient > 0.7) within-day intra-rater reliability of B-mode ultrasonography in measuring right diaphragmatic thickness among people with LBP, sufficient between-day intra-rater reliability of M-mode ultrasonography in measuring right diaphragmatic excursion in non-hospitalized individuals. The quality of evidence for all other measurement properties in various populations was low or very low. High-quality evidence supported sufficient positive correlations between diaphragm excursion and forced expiratory volume in the first second or forced vital capacity (r > = 0.3) in healthy individuals.ConclusionsDespite the reported sufficient reliability and validity of using ultrasonography to assess the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals, further large-scale studies are warranted to improve the quality of evidence regarding using ultrasonography for these measurements in clinical practice. Researchers should establish their own reliability before using various types of ultrasonography to evaluate respiratory muscle functions.Trial registrationPROSPERO NO. CRD42022322945.

B-Flow/Spatiotemporal Image Correlation M-Mode and Contrast-Enhanced/Microbubble Ultrasonography Quantification of Spiral Artery Distensibility and Placental Intervillous Perfusion in the First Trimester in a Primate Model of Impaired Spiral Artery Remodeling.

During early human pregnancy, placental trophoblasts remodel spiral arteries into distensible low-resistance vessels to promote placental perfusion. We have established a model of impaired spiral artery remodeling (SAR) by elevating estradiol levels in the first trimester of baboon pregnancy. In the present study, B-flow/spatiotemporal image correlation (STIC) M-mode ultrasonography, a non-Doppler technology for sharp rendering of vessel dimensions, was used to determine whether spiral artery distensibility was altered in SAR-suppressed baboons. Contrast-enhanced ultrasound/microbubble imaging was also performed to determine whether it detected changes in placenta intervillous space perfusion in SAR-suppressed baboons. The two imaging procedures were performed in the first trimester in baboons not treated or treated with estradiol to suppress SAR. Spiral artery distensibility, that is, luminal diameter at systole minus diameter at diastole, and volume flow as quantified by B-flow/STIC M-mode were 26% (p=0.03) and 55% (p=0.059) lower, respectively, in SAR-suppressed baboons. However, placental intervillous space flow rate and video intensity plateau levels reflecting blood perfusion, quantified by contrast-enhanced ultrasound/microbubble imaging, were unaltered in SAR-suppressed baboons. The results indicate that B-flow/STIC M-mode ultrasonography provides a non-invasive method to detect reduced distensibility and, thus, function of spiral arteries across the cardiac cycle in the first trimester in a primate model of impaired SAR. This study represents a first step in determining whether B-flow/STIC M-mode detects a similar defect in SAR early in adverse human pregnancy. This would provide an avenue to develop therapeutic modalities to prevent the devastating consequences of impaired SAR.

Evaluation of the Breastfeeding Dynamics of Neonates with Ankyloglossia via a Novel Ultrasonographic Technique.

To effectively address breastfeeding issues for neonates and mothers, one must understand the physiology of breastfeeding and the anatomical components involved in sucking, swallowing, and respiration. This study compared the tongue position and movement of neonates with tongue ties versus healthy controls during sucking. A new objective ultrasonography diagnostic approach was also introduced for the orofacial region. This retrospective study evaluated B-mode and M-mode ultrasonography images from 30 neonates clinically diagnosed with tongue tie, and a control group of 30 neonates. B-mode ultrasound images were used to examine several characteristics to locate the nipple in the oral cavity during breastfeeding. Anatomic M-mode ultrasound images were used to assess tongue movement during sucking. The nipple moved farther from the intersection of the hard and soft palates during the sucking cycle in the ankyloglossia group than in the control group (p < 0.05). Compared to the control group, neonates with ankyloglossia have a lower capacity to lift the anterior tongue toward the palate when sucking (p < 0.05). There was no significant difference in tongue movement metrics between the two groups (p > 0.05). Our findings were consistent with earlier research. The novel measurement method will offer a new perspective on breastfeeding.

Comparison between low-volume local anesthetic with intravenous dexamethasone and conventional volume without dexamethasone for superior trunk block after arthroscopic shoulder surgery: a randomized controlled non-inferiority trial

IntroductionThis study aimed to investigate whether low-volume local anesthetic with intravenous dexamethasone can reduce the incidence of diaphragmatic paresis while maintaining the analgesic duration compared with conventional volume of local...

The Importance of Tissue Doppler Imaging and M-Mode Ultrasonography in Fetuses With Preterm Premature Rupture of Membranes: A Case-Control Study.

To compare the cardiac functions of fetuses with preterm premature rupture of membranes (PPROM) between their control groups and investigate its relationship with perinatal outcomes. This prospective study was conducted with 102 pregnant women. Pregnant women with PPROM were divided into two subgroups Group A, between 26 and 30 weeks, and Group B, between 30 and 34 weeks. A control group was formed by randomly including one healthy pregnant woman for each study patient. Sociodemographic, obstetric data, tissue Doppler imaging, and M-mode imaging results were compared. The relationship between echocardiographic parameters and perinatal outcomes was also investigated. Tricuspid annular plane systolic excursion (TAPSE), S', and ET' of systolic cardiac parameters were shortened in both groups compared with their controls. Diastolic function indicator E'/A', and global function indicator myocardial performance index' increased in both groups. Isovolumetric contraction time' did not change between groups. A correlation was found between myocardial performance index', and the length of neonatal intensive care unit stay in Group A and TAPSE and duration of respiratory support and length of neonatal intensive care unit stay in Group B. The fetal cardiac function seems to be affected by PPROM, and these changes are associated with neonatal outcomes. Therefore, administering fetal cardiac function evaluation in pregnancies complicated by PPROM may help physicians establish more appropriate clinical management protocols in this special population.

Diaphragmatic ultrasound and patent ductus arteriosus in the newborn: A retrospective case series.

Patent ductus arteriosus (PDA) and diaphragmatic dysfunction are frequently seen in newborn infants but their relationship remains unknown. We aimed to use point of care ultrasound to compare diaphragmatic kinetics in infants with a PDA compared to in those without a PDA. M-mode ultrasonography was used to measure the mean inspiratory velocity (V I) in newborn infants with and without a haemodynamically significant PDA admitted in the Neonatal Unit at King's College Hospital during a three month period. Seventeen diaphragmatic ultrasound studies were reviewed from 14 infants with a median (IQR) gestational age of 26.1 (25.8-30.6) weeks, birth weight of 780 (660-1385) gr at a postnatal age of 18 (14-34) days. Eight scans had evidence of a PDA. The median (IQR) VI was significantly lower in scans with a PDA [1.01 (0.78-1.86) cm/s] compared to the ones without a PDA [3.21 (2.80-3.59) cm/s, p < 0.001]. The median (IQR) gestational age was lower in infants with a PDA [25.8 (25.6-27.3) weeks] compared to infants without a PDA [29.0 (26.1-35.1) weeks, p = 0.007]. Using multivariable linear regression analysis the VI was independently associated with a PDA (adjusted p < 0.001) but not with the gestational age (adjusted p = 0.659). Patent ductus arteriosus was associated with a lower mean inspiratory velocity in neonates and this effect was independent of gestational age.

Diaphragmatic Activation Correlated with Lumbar Multifidus Muscles and Thoracolumbar Fascia by B-Mode and M-Mode Ultrasonography in Subjects with and without Non-Specific Low Back Pain: A Pilot Study

Background and Objectives: The diaphragm, the lumbar multifidus muscles, and the thoracolumbar fascia (TLF) execute an important role in the stability of the lumbar spine and their morphology has been modified in subjects with non-specific low back pain (NS-LBP). While it is true that three structures correlate anatomically, the possible functional correlation between them has not been investigated previously in healthy subjects nor in subjects with NS-LBP. The aim of the present study was to examine this functional nexus by means of a comparison based on ultrasonographic parameters of the diaphragm, the lumbar multifidus muscles, and the TLF in subjects with and without NS-LBP. Materials and Methods: A sample of 54 (23 NS-LBP and 31 healthy) subjects were included in the study. The thickness and diaphragmatic excursion at tidal volume (TV) and force volume (FV), the lumbar multifidus muscles thickness at contraction and at rest, and the TLF thickness were evaluated using rehabilitative ultrasound imaging (RUSI) by B-mode and M-mode ultrasonography. The diaphragm thickening capacity was also calculated by thickening fraction (TF) at tidal volume and force volume. Results: There were no significant differences recorded between the activation of the diaphragm and the activation of the lumbar multifidus muscles and TLF for each variable, within both groups. However, there were significant differences recorded between both groups in diaphragm thickness and diaphragm thickening capacity at tidal volume and force volume. Conclusions: Diaphragmatic activation had no functional correlation with the activation of lumbar multifidus muscles and TLF for both groups. Nevertheless, subjects with NS-LBP showed a reduced diaphragm thickness and a lower diaphragm thickening capacity at tidal volume and force volume, compared to healthy subjects.

Validation of the Measuring Protocol for the Infraspinatus Muscle with M-Mode Ultrasound in Asymptomatic Subjects. Intra- and Inter-examiner Reliability Study

M-mode ultrasound is a reliable and valid instrument for assessing muscle activity. However, it has not been studied in any of the muscles belonging to the shoulder joint complex, particularly in the infraspinatus muscle. The aim of this study is the validation of the infraspinatus muscle activity measurement protocol with the M-mode ultrasound in asymptomatic subjects. Sixty asymptomatic volunteers were evaluated by two physiotherapists who were blinded; each of them carried out three measurements with the M-mode ultrasound in infraspinatus muscle and analysed the muscle thickness at rest and contraction, velocity of muscle activation and relaxation and Maximum Voluntary Isometric Contraction (MVIC). Intra-observer reliability was significant in both observers, showing good thickness at rest (ICC = 0.833-0.889), thickness in contraction (ICC = 0.861-0.933) and MVIC (ICC = 0.875-0.813); moderate in the activation velocity (ICC = 0.499-0.547) and relaxation velocity (ICC = 0.457-0.606). The inter-observer reliability also had good thickness at rest (ICC = 0.797), thickness in contraction (ICC = 0.89) and MVIC (ICC = 0.84); poor in relaxation time variable (ICC = 0.474) and not significant at the activation velocity (ICC = 0). The muscle activity measurement protocol of the infraspinatus muscle measured with M-mode ultrasound has been found to be reliable in asymptomatic subjects, for both the intra-examiner and inter-examiner.

Postural-respiratory function of the diaphragm assessed by M-mode ultrasonography.

ObjectivesThe diaphragm changes position and respiratory excursions during postural loading. However, it is unclear how it reacts to lifting a load while breath-holding or breathing with simultaneous voluntary contraction of the abdominal muscles (VCAM). This study analyzed diaphragm motion in healthy individuals during various postural-respiratory situations.Methods31 healthy participants underwent examination of the diaphragm using M-mode ultrasonography, spirometry, and abdominal wall tension (AWT) measurements. All recordings were performed simultaneously during three consecutive scenarios, i.e., 1. Lifting a load without breathing; 2. Lifting a load and breathing naturally; 3. Lifting a load and breathing with simultaneous VCAM.ResultsUsing paired-samples t-tests, lifting a load without breathing displaced the diaphragm’s expiratory position more caudally (P < .001), with no change noted in the inspiratory position (P = .373). During lifting a load breathing naturally, caudal displacement of the diaphragm’s inspiratory position was presented (P < .001), with no change noted in the expiratory position (P = 0.20) compared to tidal breathing. Total diaphragm excursion was greater when loaded (P = .002). Lifting a load and breathing with VCAM demonstrated no significant changes in diaphragm position for inspiration, expiration, or total excursion compared to natural loaded breathing. For all scenarios, AWT measures were greater when lifting a load (P < .001).ConclusionIn healthy individuals, caudal displacement and greater excursions of the diaphragm occurred when lifting a load. The postural function of the diaphragm is independent of its respiratory activity and is not reduced by the increase in AWT.

Prediction of Weaning Outcome from Mechanical Ventilation Using Diaphragmatic Rapid Shallow Breathing Index.

ABSTRACTBackgroundDiaphragmatic dysfunction has been increasingly documented to play a critical role to determine ventilator dependency and failure of weaning.ObjectiveThe goal was to study the diagnostic accuracy of diaphragmatic rapid shallow breathing index (D-RSBI) as a predictor of weaning outcomes in comparison to RSBI.Materials and methodsA prospective observational study on consecutively admitted patients who were intubated and mechanically ventilated for a duration of at least 48 hours was carried out. The right hemidiaphragm displacement [diaphragm displacement (DD)] was calculated by M-mode ultrasonography, and respiratory rate (RR) and tidal volume (TV) were documented from the ventilator readings. Rapid shallow breathing index (RSBI) was measured as RR/TV (in liters); D-RSBI was calculated as RR/DD (in millimeters) and expressed as breath/minute/millimeter. Extubation failure was defined as the reinstitution of mechanical ventilation at the end of, or during the spontaneous breathing trial (SBT), re-intubation or the need of noninvasive ventilation (NIV) for the patient within 48 hours of extubation.ResultsOf 101 screened patients, 50 patients met the inclusion criteria, of whom 45 patients had successful SBT, and finally, 41 patients could be successfully extubated. Hence, the overall rate of weaning failure in the study population was 18%. The areas under the receiver operator characteristic (ROC) curves for D-RSBI and RSBI were 0.97 and 0.70, respectively (p <0.0001). The Pearson's correlation among RSBI and D-RSBI was 0.81 (p-value <0.001).ConclusionDiaphragmatic rapid shallow breathing index has a positive correlation and greater diagnostic accuracy than RSBI, the conventional weaning index.How to cite this articleShamil PK, Gupta NK, Ish P, Sen MK, Kumar R, Chakrabarti S, et al. Prediction of Weaning Outcome from Mechanical Ventilation Using Diaphragmatic Rapid Shallow Breathing Index. Indian J Crit Care Med 2022;26(9):1000–1005.

Impact of an extrafascial versus intrafascial injection for supraclavicular brachial plexus block on respiratory function: a randomized, controlled, double-blind trial

IntroductionHemidiaphragmatic paresis after ultrasound-guided supraclavicular brachial plexus block is reported to occur in up to 67% of patients. We tested the hypothesis that an injection outside the brachial plexus sheath...

The Amplitude of Diaphragm Compound Muscle Action Potential Correlates With Diaphragmatic Excursion on Ultrasound and Pulmonary Function After Supraclavicular Brachial Plexus Block.

ObjectiveThis prospective, double-blind, randomized study assessed (1) the associations between diaphragm compound muscle action potential (CMAP), hemidiaphragmatic excursion, and pulmonary function after supraclavicular brachial plexus block (SCBPB) and (2) diagnostic efficacy of pulmonary function for hemidiaphragmatic paralysis evidenced by diaphragm CMAP as an assessment of diaphragm strength was evaluated.MethodsEighty-six patients were scheduled for the removal of hardware after healing of a right upper limb fracture distal to the shoulder who were randomly assigned in a 1:1 ratio to two groups: Group A (diaphragmatic excursion), or Group B (pulmonary function). Phrenic nerve conduction studies (PNCSs), M-mode ultrasonography of the diaphragm, and pulmonary function tests (PFTs) were performed before and 30 min after SCBPB. PNCSs were used to determine the latency and amplitude of diaphragm CMAP. Ultrasonography of the diaphragm was performed with patients in a supine position using a low-frequency probe over the subcostal space at the midclavicular line. The diaphragmatic excursion was measured during quiet breathing and deep breathing. Pulmonary function, i.e., forced vital capacity (FVC), predicted value of FVC, and forced expiratory flow in the first second (FEV1), was measured with spirometry. Receiver Operating Characteristic (ROC) curve analysis was used to assess the diagnostic efficacy of pulmonary function for hemidiaphragmatic paralysis evidenced by diaphragm CMAP as an assessment of diaphragm strength.ResultsThere were significant associations between the reduction in amplitude of diaphragm CMAP and reductions in diaphragmatic excursion during quiet breathing (r = 0.70, p < 0.01) and deep breathing (r = 0.63, p < 0.01) when expressed as a percentage of baseline values. There were significant associations between the reduction in amplitude of diaphragm CMAP and reductions in FVC (r = 0.67, p < 0.01), FVC% (r = 0.67, p < 0.01), and FEV1 (r = 0.62, p < 0.01), when expressed as percentage of baseline values. The area under the ROC curve for FVC was 0.86. A decrease of >8.4% in FVC compared to pre-block predicted hemidiaphragmatic paralysis (determined by diaphragm CMAP) with sensitivity and specificity of 79.2 and 100%, respectively.ConclusionsThe relative reduction in diaphragm CMAP amplitude after SCBPB was correlated with relative reductions in diaphragmatic excursion and pulmonary function. FVC has potential as a useful diagnostic indicator of hemidiaphragmatic paralysis, evidenced by diaphragm CMAP, after SCBPB. These data establish diaphragm CMAP as a direct and objective index of diaphragmatic paralysis after SCBPB.

B-flow/spatiotemporal image correlation M-mode: novel ultrasound method that detects decrease in spiral artery luminal diameter in first trimester in primate model of impaired spiral artery remodeling.

ABSTRACTObjectiveTo determine if B‐flow/spatiotemporal image correlation (STIC) M‐mode ultrasonography detects a decrease in spiral artery luminal diameter and volume flow during the first trimester in a non‐human primate model of impaired spiral artery remodeling (SAR).MethodsPregnant baboons were treated daily with estradiol benzoate on days 25–59 of the first trimester (term, 184 days), or remained untreated. On day 60 of gestation, spiral artery luminal diameter (in seven untreated and 12 estradiol‐treated baboons) and volume flow (in four untreated and eight estradiol‐treated baboons) were quantified by B‐flow/STIC M‐mode ultrasonography. In addition, in 15 untreated and 18 estradiol‐treated baboons, the percent of spiral arteries remodeled by extravillous trophoblasts was quantified ex vivo by immunohistochemical image analysis on placental basal plate tissue collected via Cesarean section on day 60. Findings were compared between treated and untreated animals. The correlation between spiral artery luminal diameter and percent of SAR was assessed in three untreated and six estradiol‐treated baboons which underwent both B‐flow/STIC M‐mode ultrasound and quantification of SAR.ResultsThe proportion of spiral arteries greater than 50 µm in diameter remodeled by extravillous trophoblasts was 70% lower in estradiol‐treated baboons than in untreated animals (P = 0.000001). Spiral artery luminal diameter in systole and diastole, as quantified by B‐flow/STIC M‐mode in the first trimester of pregnancy, was 31% (P = 0.014) and 50% (P = 0.005) lower, respectively, and volume flow was 85% lower (P = 0.014), in SAR‐suppressed baboons compared with untreated animals. There was a significant correlation between spiral artery luminal diameter as quantified by B‐flow/STIC M‐mode ultrasonography and the percent of SAR (P < 0.05).ConclusionB‐flow/STIC M‐mode ultrasonography provides a novel real‐time non‐invasive method to detect a decrease in uterine spiral artery luminal diameter and volume flow during the cardiac cycle, reflecting decreased distensibility of the vessel wall, in the first trimester in a non‐human primate model of defective SAR. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Ultrasound-Guided Clavipectoral Fascial Plane Block With Intermediate Cervical Plexus Block for Midshaft Clavicular Surgery: A Prospective Randomized Controlled Trial.

Regional anesthesia such as interscalene brachial plexus block (ISBPB) with intermediate cervical plexus block (ICPB) is generally a preferred choice for clavicular surgery. However, various studies have shown that these blocks, especially ISBPB, could cause phrenic nerve paralysis and decrease diaphragmatic motion. The study aimed to evaluate the efficacy of clavipectoral fascial plane block (CPB), an alternative technique to ISBPB, with ICPB, in reducing hemidiaphragmatic paralysis during midshaft clavicular surgery. Forty patients scheduled for right midshaft clavicular surgery were randomized (1:1) into an ultrasound-guided ISBPB with ICPB (BC) group or ultrasound-guided CPB with ICPB (CC) group. Five milliliter of 0.375% ropivacaine was used for ICPB, another 20 mL for ISBPB or CPB, and no administration of additional sedative or general anesthetic was planned. Primary outcome was measured by the incidence of hemidiaphragmatic paralysis using M-mode ultrasonography, while secondary outcomes were measured by bedside pulmonary function test, the success rate of block, the time required for the block procedure and onset of block, and motor block score in right upper extremity. In comparison with BC group, the incidence of hemidiaphragmatic paralysis postblock was decreased in CC group (50% vs 0%; P < .001), and measurement of bedside pulmonary function was significantly improved. There was a 100% success rate for anesthetic block in both BC and CC groups, and CC group showed lower motor block score in upper extremity and less block procedure time than BC group (7.1 ± 1.2 vs 3.2 ± 0.6 minutes; P < .001). Moreover, no significant differences were found between time of onset of block and other anesthetic complications in the 2 groups. Ultrasound-guided CPB with ICPB could significantly reduce hemidiaphragmatic paralysis and provide an adequate surgical anesthesia with fewer complications such as motor block in upper extremity during right midshaft clavicular surgery.