Diaphragm Motion Research Articles

Association between diaphragmatic dysfunction after adult cardiovascular surgery and prognosis of mechanical ventilation: a retrospective cohort study

BackgroundDiaphragmatic dysfunction often occurs after adult cardiovascular surgery. The prognostic effect of diaphragmatic dysfunction on ventilatory management in patients after cardiovascular surgery is unknown. This study aimed to investigate the association between diaphragmatic dysfunction and prognosis of ventilatory management in adult postoperative cardiovascular surgery patients.MethodsThis study was a single-center retrospective cohort study conducted at a tertiary care university hospital. This study included adult patients admitted to the intensive care unit under tracheal intubation after cardiovascular surgery. Spontaneous breathing trial was performed, and bilateral diaphragmatic motion was assessed using ultrasonography; diaphragmatic dysfunction was classified as normal, incomplete dysfunction, or complete dysfunction. The primary outcome was weaning off in mechanical ventilation. The duration of mechanical ventilation was defined as duration from the date of ICU admission to the date of weaning off in mechanical ventilation. The secondary outcomes were reintubation, death from all causes, improvement of diaphragm position assessed by chest radiographs. The subdistribution hazard ratio or hazard ratio (HR) with 95% confidence of intervals (CIs) were estimated by Fine-Gray models or Cox proportional hazard models adjusted for potential confounders.ResultsOf 153 patients analyzed, 49 patients (32.0%) had diaphragmatic dysfunction. Diaphragmatic dysfunction consisted of incomplete dysfunction in 38 patients and complete dysfunction in 11 patients. Diaphragmatic dysfunction groups had longer duration of mechanical ventilation (68 h [interquartile range (IQR) 39–114] vs 23 h [15–67], adjusted subdistribution HR 0.63, 95% CIs 0.43–0.92). There was a higher rate of reintubation (12.2% vs 2.9%, univariate logistic regression analysis p = 0.034, unadjusted odds ratio = 4.70, 95% CIs 1.12–19.65), and a tendency to have higher death from all causes in the diaphragmatic dysfunction group during follow-up period (maximum 6.5 years) (18.4% vs 9.6%, adjusted HR 1.64, 95% CIs 0.59–4.53). The time to improvement of diaphragm position on chest radiograph was significantly longer in the diaphragmatic dysfunction group (14 days [IQR 6–29] vs 5 days [IQR 2–10], adjusted subdistribution HR 0.54, 95% CIs 0.38–0.77).ConclusionsDiaphragmatic dysfunction after adult cardiovascular surgery was significantly associated with longer duration of mechanical ventilation and higher reintubation.

Abstract P342: Acute Nasal Breathing Lowers Blood Pressure And Increases Parasympathetic Contributions To Heart Rate Variability In Young Adults

Introduction: Interest is growing in how breathing pace, pattern, and training (e.g., device-assisted or -resisted breathing) affect prognostic cardiovascular variables (e.g., blood pressure (BP)). Nasal breathing increases bronchodilation via airway epithelium nitric oxide production, increases diaphragmatic movement, and reduces accessory inspiratory muscle recruitment. Despite these changes, the effect of nasal compared with oral breathing (i.e., breathing route) on prognostic cardiovascular variables is unclear. Hypothesis: We hypothesized that nasal compared with oral breathing would acutely lower BP and improve heart rate variability (HRV) metrics. Methods: We tested 20 young healthy adults in this study (13 Female/7 Male; age: 18 [1] years, median [IQR]; body mass index: 23 ± 2 kg•m -2 , screening systolic / diastolic BP 116 ± 12 / 67 ± 7 mmHg mean ± SD). Participants self-selected their breathing rate during a five-minute ‘run-in’ period. Using a metronome, their breathing rate was fixed during two subsequent (random order) five-minute resting periods with nasal and oral breathing while we measured brachial BP and HRV metrics via ECG. We compared data between conditions using a Wilcoxon signed-rank paired test (data presented as median [IQR]) or using paired, two-tailed t-tests (data presented as mean ± SD). We set the significance to p <0.05. Results: Nasal breathing lowered mean (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, p =0.006, Cohen’s d =0.70) and diastolic (nasal: 68 [8] vs. oral: 72 [5] mmHg, p <0.001, Rank-biserial correlation=0.89), but not systolic (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, p =0.48, Cohen’s d =0.16) BP. Nasal breathing also raised the High-Frequency contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21 %, p =0.04, Cohen’s d =0.50) and lowered the Low-Frequency to High-Frequency ratio (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, p =0.04, Cohen’s d =0.49), suggesting a greater parasympathetic contribution to HRV. There were no differences between conditions for heart rate ( p= 0.90) or time-domain HRV metrics ( ps ≥0.07; e.g., the standard deviation of NN intervals). Conclusion: These data suggest that nasal compared with oral breathing acutely lowers mean and diastolic BP as well as potentially increases parasympathetic contributions to HRV.

Continuous thoracic epidural versus continuous paravertebral analgesia in patients undergoing open renal surgery: Evaluation of pulmonary function; randomized double-blinded clinical trial

ABSTRACT Background This study aimed to assess pulmonary functions after either continuous thoracic paravertebral block (cTPVB) or thoracic epidural block (cTEB) in open renal surgeries. Methodsː The double-blinded, randomized clinical trial included 40 patients scheduled for open renal surgeries at Urology Hospital-Assiut University, equally assigned into group E (n = 20) and group P (n = 20), both at the level of 7th-8th thoracic vertebra. Initially, 7.5–12 mL of bupivacaine 0.25% was started before the induction of general anesthesia, followed by bupivacaine 0.125% continuously at a rate of 5–15 ml/h. Forced vital capacity (FVC) measured every 6 hours postoperatively within the first 24 hours was the primary outcome. Secondary outcomes were peak expiratory flow rate (PEFR), forced expiratory volume in the first second (FEV1), diaphragmatic excursion (DE), postoperative analgesia, total opioid consumption, total local anesthetic dose, hemodynamics and complications. Resultsː FVC, FEV1 and DE were better preserved in cTPVB where the lowest postoperative readings as a fraction of preoperative control were 0.7 ± 0.11 vs 0.65 ± 0.11 L, 0.74 ± 0.11 vs 0.64 ± 0.10 L and 0.73 ± 0.1 vs 0.58 ± 0.1 cm, respectively. The lowest postoperative PEFR was reported in cTEB (p-value = 0.128). Analysis of numeric rating pain scale, total opioid consumption and time of first rescue analgesic request revealed a statistical nonsignificant difference. The total infused dose of local anesthetic was significantly higher in cTPVB group. Incidence of sympatholytic complications was higher in cTEB. Conclusion cTEB and cTPVB had convergent effect on respiratory function and diaphragmatic motility and equivalent analgesic efficacy after open renal surgeries. Although cTPVB was technically easier and less time-consuming than cTEB, higher dose of local anaesthetic was required in cTPVB.

THE EFFECT OF TECAR THERAPY USING WINBACK ON DIAPHRAGM MOVEMENT AND CHEST MOBILITY IN ADULTS WITH LIMITED CHEST MOBILITY

The diaphragm is an essential respiratory muscle that accounts for 70% of the inspiratory function during stable breathing. Diaphragm weakness leads to decreased thoracic mobility due to inspiratory assist muscles overuse. It is closely related to respiratory dysfunction. This study aims to define the effect of TECAR therapy using Winback on diaphragm movement and chest mobility in adults with limited chest mobility. Thirty-six young adults with limited chest mobility were selected as participants in this study. TECAR therapy was applied to the participant’s diaphragm for 15[Formula: see text]min. Ultrasound measured each group’s diaphragm movement, and a tape measure was used to measure chest mobility. A paired t-test analyzed each group’s diaphragm movement and chest mobility change, and an independent t-test analyzed the difference in the amount of change between groups. The value was set to 0.05. As a result, after the intervention, diaphragm movement (unit: cm) significantly increased from [Formula: see text] to [Formula: see text] ([Formula: see text]). Upper chest movement (unit: cm) significantly increased from [Formula: see text]-[Formula: see text], middle chest movement (unit: cm) increased from [Formula: see text]-[Formula: see text], and lower chest movement (unit: cm) increased from [Formula: see text]-[Formula: see text] ([Formula: see text]). The results provide innovative clinical evidence that TECAR therapy significantly affected diaphragm movement and chest mobility improvement in young adults with limited chest mobility.

Novel simulation for dosimetry impact of diaphragm respiratory motion in four-dimensional volumetric modulated arc therapy for esophageal cancer

Background and purposeThe diaphragm respiratory motion (RM) could impact the target dose robustness in the lower esophageal cancer (EC). We aimed to develop a framework evaluating the impact of different RM patterns quantitatively in one patient, by creating virtual four-dimensional computed-tomography (v4DCT) images, which could lead to tailored treatment for the breathing pattern. We validated virtual 4D radiotherapy (v4DRT) along with exploring the acceptability of free-breathing volumetric modulated arc therapy (FB-VMAT). Methods and MaterialsWe assessed 10 patients with superficial EC through their real 4DCT (r4DCT) scans. v4DCT images were derived from the end-inhalation computed tomography (CT) image (reference CT) and the v4DRT dose was accumulated dose over all phases. r4DRT diaphragm shifts were applied with magnitudes derived from r4DCT scans; clinical target volume (CTV) dose of v4DRT was compared with that of r4DRT to validate v4DRT. CTV dosage modifications and planning organ at risk volume (PRV) margins of the spinal cord were examined with the diaphragm movement. The percentage dose differences (ΔDx) were determined between the v4DRT and the dose calculated on the reference CT image. ResultsThe CTV ΔDx between the r4DRT and v4DRT were within 1% in cases with RM ≦ 15 mm. The average ΔD100% and ΔDmean of the CTV ranging from 5 to 15 mm of diaphragm motion was 0.3% to 1.7% and 0.1% to 0.4%, respectively. All CTV index changes were within 3% and ΔD1cc and ΔD2cc of Cord PRV were within 1%. ConclusionWe postulate a novel method for evaluating the CTV robustness, comparable to the conventional r4DCT method under the diaphragm RM ≦ 15 mm permitting an impact of within 3% in FB-VMAT for EC on the CTV dose distribution.

Ultrasound assessment of endotracheal tube depth in neonates: a prospective feasibility study

ObjectiveTo examine the reliability of a novel ultrasound (US) method for assessment of endotracheal tube (ETT) position in neonates.DesignProspective, observational, single-centre, feasibility study.SettingLevel III neonatal intensive care unit.PatientsTerm and preterm...

Development of a prediction model for target positioning by using diaphragm waveforms extracted from CBCT projection images.

To develop a prediction model (PM) for target positioning using diaphragm waveforms extracted from CBCT projection images. Nineteen patients with lung cancer underwent orthogonal rotational kV x-ray imaging lasting 70 s. IR markers placed on their abdominal surfaces and an implanted gold marker located nearest to the tumor were considered as external surrogates and the target, respectively. Four different types of regression-based PM were trained using surrogate motions and target positions for the first 60 s, as follows: Scenario A: Based on the clinical scenario, 3D target positions extracted from projection images were used as they were (PMCL ). Scenario B: The short-arc 4D-CBCT waveform exhibiting eight target positions was obtained by averaging the target positions in Scenario A. The waveform was repeated for 60 s (W4D-CBCT ) by adapting to the respiratory phase of the external surrogate. W4D-CBCT was used as the target positions (PM4D-CBCT ). Scenario C: The Amsterdam Shroud (AS) signal, which depicted the diaphragm motion in the superior-inferior direction was extracted from the orthogonal projection images. The amplitude and phase of W4D-CBCT were corrected based on the AS signal. The AS-corrected W4D-CBCT was used as the target positions (PMAS-4D-CBCT ). Scenario D: The AS signal was extracted from single projection images. Other processes were the same as in Scenario C. The prediction errors were calculated for the remaining 10 s. The 3D prediction error within 3mm was 77.3% for PM4D-CBCT , which was 12.8% lower than that for PMCL . Using the diaphragm waveforms, the percentage of errors within 3mm improved by approximately 7% to 84.0%-85.3% for PMAS-4D-CBCT in Scenarios C and D, respectively. Statistically significant differences were observed between the prediction errors of PM4D-CBCT and PMAS-4D-CBCT . PMAS-4D-CBCT outperformed PM4D-CBCT , proving the efficacy of the AS signal-based correction. PMAS-4D-CBCT would make it possible to predict target positions from 4D-CBCT images without gold markers.

A Fully Wireless and Batteryless Localization System with 50 Micrometre Motion Detection Capability and Adaptive Transmitter Power Control for Point-of-Care Biomedical Applications.

Localization has varied applications in biomedicine, such as wireless capsule endoscopy (WCE), detection of cancerous tissue, drug delivery, robotic surgeries, and brain mapping. Currently, most localization systems are battery-powered and suffer from issues regarding battery leakage and limited battery life, resulting in potential health hazards and inconveniences when using them for continuous health monitoring applications. This paper proposes an entirely wireless and battery-less 2D localization system consisting of an integrated circuit (IC) that is wirelessly powered at a distance of 4 cm by a 40.68 MHz radio frequency (RF) power of only 2 W. The proposed localization system wirelessly transmits a locked sub-harmonic 13.56 MHz signal generated from the wirelessly received 40.68 MHz RF power signal, eliminating the need for a power-hungry oscillator. Additionally, the system, having a measurement latency of 11.3 ms, has also been verified to sense motion as small as 50 μm as well as measure the rate of motion up to 10 beats per minute, therefore extending its application to the detection of physiological motions such as diaphragm motion during breathing. The localizer has a small form factor of 17 mm × 12 mm × 0.2 mm and consumes an average power of 6 μW. Ex vivo measurements using the localizer inside the porcine intestine demonstrate a localization accuracy of less than 5 mm.

What to do when hiccups are coming? A case report

Hiccup known as innocuous symptom and usually self-limiting within seconds or minutes. The process of hiccup related to involuntary movement, intermitent and repetitive contractions of diaphragm and lead to abrupt early closure of glottis. We report a case of 57-year-old man with 5 days chronic hiccup, following with coughing, nausea, vomiting and seizure. Patient was hospitalized 4 days and getting better after given antibiotic, proton pump inhibitor (PPI) therapy and symptomatic drug due to hiccup.

Impaired diaphragmatic motility in treatment-naive adult patients with spinal muscular atrophy improved during nusinersen treatment.

The leading clinical feature of 5q-associated spinal muscular atrophy (SMA) is symmetric, proximal muscle weakness. Muscles involved in ventilation exhibit a specific pattern of denervation: intercostal muscles are severely atrophic, whereas the diaphragm muscle is less affected. The aim of this study was to investigate the involvement of diaphragmatic function by ultrasound imaging in adult patients with SMA and to quantify dynamics of diaphragmatic function during nusinersen treatment. Diaphragmatic thickness, thickening, and excursion during quiet breathing were assessed in 24 adult patients with SMA type 2 and 3 by diaphragm ultrasound imaging before and during nusinersen treatment and were correlated with spirometric parameters. Diaphragm thickness was not reduced, but increased in a remarkable proportion of patients, whereas diaphragm thickening and excursion were reduced in about 20% to 30% of nusinersen-naive, adult patients with SMA types 2 and 3. During 26 months of nusinersen treatment, diaphragm thickening fraction and excursion improved. Diaphragm ultrasound imaging can provide disease- and treatment-relevant information that is not identified during routine clinical assessments and may therefore be a valuable complementary outcome measure.

Comparison of the analgesic efficacy between arthroscopically placed continuous suprascapular nerve block and ultrasound-guided continuous superior trunk block: a double-blinded randomized controlled trial.

Single-shot suprascapular nerve block and superior trunk block have been reported to provide a non-inferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides non-inferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery. We randomized 100 patients undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared. Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a non-inferiority margin of 1 (worst pain score, mean difference: 0.9, 95% CI 0.1 to 1.7; resting pain score: mean difference: 0.5, 95% CI 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group. Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

Diaphragm and abdominal organ motion during radiotherapy: a comprehensive multicenter study in 189 children

BackgroundFor accurate thoracic and abdominal radiotherapy, inter- and intrafractional geometrical uncertainties need to be considered to enable accurate margin sizes. We aim to quantify interfractional diaphragm and abdominal organ position variations, and intrafractional diaphragm motion in a large multicenter cohort of pediatric cancer patients (< 18 years). We investigated the correlation of interfractional position variations and intrafractional motion with age, and with general anesthesia (GA).MethodsIn 189 children (mean age 8.1; range 0.4–17.9 years) from six institutes, interfractional position variation of both hemidiaphragms, spleen, liver, left and right kidneys was quantified using a two-step registration. CBCTs were registered to the reference CT relative to the bony anatomy, followed by organ registration. We calculated the group mean, systematic and random errors (standard deviations Σ and σ, respectively) in cranial-caudal (CC), left-right and anterior-posterior directions. Intrafractional right hemidiaphragm motion was quantified using CBCTs on which the breathing amplitude, defined as the difference between end-inspiration and end-expiration peaks, was assessed (N = 79). We investigated correlations with age (Spearman’s ρ), and differences in motion between patients treated with and without GA (N = 75; all < 5.5 years).ResultsInterfractional group means were largest in CC direction and varied widely between patients, with largest variations in the right hemidiaphragm (range -13.0–17.5 mm). Interfractional group mean of the left kidney showed a borderline significant correlation with age (p = 0.047; ρ = 0.17). Intrafractional right hemidiaphragm motion in patients ≥ 5.5 years (mean 10.3 mm) was significantly larger compared to patients < 5.5 years treated without GA (mean 8.3 mm) (p = 0.02), with smaller Σ and σ values. We found a significant correlation between breathing amplitude and age (p < 0.001; ρ = 0.43). Interfractional right hemidiaphragm position variations were significantly smaller in patients < 5.5 years treated with GA than without GA (p = 0.004), but intrafractional motion showed no significant difference.ConclusionIn this large multicenter cohort of children undergoing thoracic and abdominal radiotherapy, we found that interfractional position variation does not depend on age, but the use of GA in patients < 5.5 years showed smaller systematic and random errors. Furthermore, our results showed that breathing amplitude increases with age. Moreover, variations between patients advocate the need for a patient-specific margin approach.

Numerical simulation of fuel supply of multi-tandem fuel tanks in flight vehicle

Multi-tandem fuel tanks have a complex structure, low flow rate between tanks, and, unlike single-fuel tanks, uneven pressure distribution, which makes their fuel supply and pressurization difficult to control. This paper uses a volume-of-fluid model based on the finite-volume method to track the fuel motion in different states of a flight vehicle and obtains the liquid-surface sloshing and the liquid flow in the connecting pipe. The model uses the dynamic meshing technique combined with the pressure at the solid wall to track the motion of the one-way stop valve diaphragm in the connecting pipe, thereby better predicting the fuel transfer in the connecting pipe. The calculation covers the whole process of flight vehicle erection, standby, flight, pumping, and pressurization and provides the distribution of pressure in different fuel tanks and the fuel flow characteristics in the connecting pipe. The calculation results are consistent with the experimental results, which verifies the accuracy of the model. By calculating different working cases, the results show that the different states of the flight vehicle strongly affect the sloshing of the liquid in the fuel tank, the pressure distribution, and the opening and closing of the valves. The maximum mass flow rate through the three valves, pressure at the bottom of the tank, and pressure at the pumping port all increase after the pressurization in the fuel tank. The flow of fuel between different tanks can be increased by changing the structure of the connecting pipe, which affects the pressure at different locations in the tank and at the pumping port.

Atracurium Versus Cis-Atracurium for Laryngeal Relaxation and Hemodynamic Stability in Pediatric Patients: A Randomized, Double-Blind Study.

Background and aim Equipotent dose of atracurium and cis-atracurium has failed to show clinically equi-effective muscle relaxation actions required for laryngoscopy and endotracheal intubation (LETI) in adults. There needs to be more data on children. We aimed to compare the efficacy of equipotent atracurium and cis-atracurium for producing optimal LETI. We also compared the hemodynamic stability and side effects. Methods With approvals and informed consent, 104 children between three and 12 years were enrolled in the present randomized, double-blind, parallel-arm study. Fifty-two participants were recruited in each group and received either 2ED95 atracurium (0.5mg/kg) or 2ED95 cis-atracurium (0.1mg/kg). Three-point scale, i.e., excellent, good, and poor, were assigned based on jaw relaxation, vocal cords, diaphragmatic movement, coughing, and resistance to the laryngoscope blade. Basic hemodynamics and adverse events like flushing, hemodynamic instability, and airway spasms were noted. The groups were compared using Wilcoxon-Mann-Whitney U or Chi-square tests as applicable; a p-value <0.05 was considered significant. Results Entire enrolled participants completed the study. Excellent LETI conditions were significantly higher in the atracurium than in cis-atracurium (53.8% versus 19.2%, p-value <0.001). In the present study, blunted laryngoscopy-related sympathetic surge containing the increase in hemodynamic parameters within 20% from the baseline was noted in both groups, but the blunting and fall back of hemodynamic towards the baseline was rapid in the atracurium (within 7 minutes of LETI) group than cis-atracurium, i.e., 72 minutes; p-value <0.001. Only one flushing was noted in the atracurium group compared to none in the cis-atracurium. Conclusion 2ED95 dose of cis-atracurium (0.1mg/kg), although have minor advantages of maintaining hemodynamic better, has lower adverse events, it provides significantly lower 'Excellent LETI conditions' when compared to 2ED95 dose of atracurium (0.5mg/kg) in children of age three to 12 years.

Agreement between Diaphragm Ultrasound and Pulmonary Function Testing in the Evaluation of Diaphragm Function in Patients with ALS

Background: In ALS patients, diaphragmatic dysfunction is usually assessed by pulmonary function testing (PFTs) that requires patient cooperation. Evidence suggest that diaphragm ultrasound (DU) can be utilized, as an alternative to PFTs, to detect reduced diaphragmatic motility in ALS patients. This study aimed to verify the agreement between the results obtained by DU with those obtained by PFTs in both standing-up and supine positions.Methods: Twenty nine spinal ALS and thirteen healthy controls were studied in standing up and lying 30° supine position. All subjects performed PFTs and DU, to assess of diaphragmatic excursion, delta-thickness between end inspiration and end expiration (ΔT), and the thickening fraction (TF). Results: The standing position, ΔT correlates with VC (r=0.58p=0.001) and FVC (r=0.61 p&lt;0.001); in lying 30° supine position, ΔT correlates with VC(r=0.59 p=0.001) and FVC (r=0.62 p&lt;0.001). In standing up position, TF correlates with VC (r=0.55 p=0.003) and FVC (r=0.53 p=0.005); in lying 30° supine position, TF correlates with VC (r=0.55 p=0.003) and FVC (r=0.51 p=0.007). The following correlations were also observed: the standing position, diaphragmatic excursion correlated with VC(r=0.55 p=0.007) and FVC (r =0.65 p&lt;0.001). In lying 30° supine position, diaphragmatic excursion correlated with VC(r=0.59 p=0.003); and FVC(r=0.63 p=0.001).Conclusion: DU adequately assesses the diaphragmatic impairment in ALS patients. Thickening and excursion appear as complementary indices in the evaluation of diaphragm motility.

Upward Diaphragm Motion on Four-Dimensional Computed Tomography in Severe Diaphragm Weakness.

"Upward Diaphragm Motion on Four-Dimensional Computed Tomography in Severe Diaphragm Weakness." American Journal of Respiratory and Critical Care Medicine, 0(ja), pp.

A case of a transient phrenic nerve paralysis after resection of a giant lymphangioma evaluated by dynamic digital radiography

BackgroundLymphangioma is a relatively rare benign congenital malformation composed of dilated cystic lymphatic vessels; however, its occurrence in adults and manifestation as mediastinal lymphangioma are even rarer. In general, the incidence of mediastinal lymphangiomas has been reported to range from 0.01 to 4.5% of all mediastinal tumors. Mediastinal lymphangiomas tend to increase in size and can sometimes stretch the phrenic nerve that are present in the mediastinum, resulting in phrenic nerve palsy.Dynamic digital radiography (DDR) allows for quantitative evaluation over time and has recently been utilized in actual clinical practice. The distance between the apex of the lung and diaphragm can be measured, and the movement of the left and right lungs and diaphragm can be evaluated separately. In this report, we describe a case in which DDR demonstrated the improvement of phrenic nerve palsy.Case presentationA 32-year-old woman with no medical history and no smoking history reported dyspnea on exertion, and abnormalities were noted on chest X-ray. Close examinations revealed thymic, pericardial, bronchogenic, and teratoid cysts, and since they appeared to be growing in size, the patient was referred for surgery. Because the giant cyst prevented visualization of the thoracic cavity, puncture was performed for aspiration. The stretched phrenic nerve was identified in the giant cyst wall and was dissected to avoid damaging it. The cyst wall was detachable and excised without obvious mediastinal invasion. The patient had a good postoperative course and was discharged on postoperative day 5. Dynamic digital radiography on postoperative days 3 and 17 showed movement of the left diaphragm, with improvement over time.ConclusionsMediastinal lymphangiomas tend to grow in size and can sometimes stretch the phrenic nerves that are present in the mediastinum, resulting in phrenic nerve palsy. Dynamic digital radiography (DDR) is a modality that can also be evaluated quantitatively and over time and can comprehensively determine improvement in transverse paralysis.

Transvenous stimulation yields exposure-dependent protection from ventilator-induced diaphragm atrophy.

Mechanical ventilation (MV)-induced diaphragmatic atrophy can contribute to weaning difficulties. A temporary transvenous diaphragm neurostimulation (TTDN) device that elicits diaphragm contractions has previously been shown to mitigate atrophy during MV in a preclinical model; however, its effects on different myofiber types remain unknown. It is important to examine these effects, as each myofiber type plays a role in the range of diaphragmatic movements to ensure successful liberation from MV. Eighteen pigs were assigned to one of three ventilation conditions for 50 hours: MV-Only and TTDN contracting the diaphragm every other breath or every breath synchronously with MV (TTDN50% + MV and TTDN100% + MV, respectively). Six pigs were assigned to a never-ventilated, never-paced (NV-NP) group. Diaphragm biopsies were fiber-typed, and myofiber cross-sectional areas were measured and normalized to subject weight. There were effect differences based on TTDN exposure. The TTDN100% + MV group showed less atrophy in Type 2A and 2X myofibers than the TTDN50% + MV group, relative to the NV-NP group. The TTDN50% + MV animals showed less MV-induced atrophy in type 1 myofibers than TTDN100% + MV animals. Additionally, there were no significant differences in proportions of myofiber types between each condition. TTDN applied synchronously with MV for 50 hours mitigates MV-induced atrophy in all myofiber types, with no evidence of stimulation-induced myofiber-type shift. At this stimulation profile, enhanced protection for type 1 myofibers and type 2 myofibers was seen when diaphragm contractions occurred every other breath and every breath, respectively.NEW & NOTEWORTHY This research adds to our current understanding of applying temporary transvenous diaphragmatic neurostimulation (TTDN) synchronously with mechanical ventilation by examining its diaphragm-myofiber effects. We observed that using this therapy for 50 hours with mechanical ventilation not only mitigated ventilator-induced atrophy on all myofiber types with dose effects, it also did not invoke alterations in diaphragm myofiber type proportions. These findings suggest that applying TTDN with mechanical ventilation at different doses represents its broad spectrum use and viability as a diaphragm protective strategy.

Prolonged Normothermic Machine Perfusion: Buying More Time for Liver Graft Assessment and Repair.

Prolonged Normothermic Machine Perfusion: Buying More Time for Liver Graft Assessment and Repair.

Association of Internal and External Motion Based on Cine MR Images Acquired During Real-Time Treatment on MRI–Guided Linear Accelerator for Patients With Lung Cancer

With the recent clinical implementation of magnetic resonance imaging (MRI)-guided linear accelerators, a large number of real-time planar MR images has been acquired during lung cancer treatment as a standard of care. In this study, associations among lung tumor, diaphragm, and external skin movement were studied based on MR cine imaging during the entire duration of each treatment fraction. This retrospective study used 181,798 planar MRI frames acquired over 55 treatment/imaging sessions of 13 patients with lung cancer treated on 2 MRI-guided linear accelerators. From each planar MR image frame, in-house software automatically extracted 9 features: the superior-interior (SI) and posterior-anterior (PA) positions of a lung tumor; the area of the lung (Lung_Area); the posterior (Dia_Post), dome/apex (Dia_Dome), and anterior (Dia_Ant) points of a diaphragmatic curve; the diaphragm curve point (Dia_Max); and the chest (Chest) and belly (Belly) skin points experienced the maximum range of motions. Correlation analyses were performed among the 9 features for every session. Lung tumor motion range and standard deviations were calculated based on positions obtained in cine images and compared with motion ranges obtained from 4-dimensional computed tomography images. In the study, 177,009 frames of images were successfully analyzed. For all patients, correlation coefficients were as follows: 0.91 ± 0.10 between any 2 features among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.82 ± 0.21 between SI and any feature among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.75 ± 0.24 between SI and Belly. Six of 13 patients were considered large amplitude motion (patients with lung tumor SI motion standard deviation >5 mm). Furthermore, 92,956 frames of images were analyzed for the 6 large-amplitude motion patients. For this set, correlation coefficients were 0.93 ± 0.07 between any 2 features among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; 0.94 ± 0.06 between SI and any feature among Lung_Area, Dia_Post, Dia_Dome, and Dia_Max; and 0.90 ± 0.09 between SI and Belly. Both belly and diaphragmatic motions as assessed by cine MRI are highly correlated with large amplitude lung tumor motion in the longitudinal axis.