The course of diaphragm atrophy in ventilated patients assessed with ultrasound: a longitudinal cohort study.
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SUBMITTER: Schepens T
PROVIDER: S-EPMC4671211 | biostudies-literature | 2015 Dec
REPOSITORIES: biostudies-literature
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The course of diaphragm atrophy in ventilated patients assessed with ultrasound: a longitudinal cohort study.
Schepens Tom T Verbrugghe Walter W Dams Karolien K Corthouts Bob B Parizel Paul M PM Jorens Philippe G PG
Critical care (London, England) 20151207
<h4>Introduction</h4>Mechanical ventilation and the effect of respiratory muscle unloading on the diaphragm cause ventilator-induced diaphragmatic dysfunction (VIDD). Atrophy of the diaphragmatic muscle is a major part of VIDD, and has a rapid onset in most animal models. We wanted to assess the clinical evolution and risk factors for VIDD in an adult intensive care unit (ICU) by measuring diaphragm thickness using ultrasound.<h4>Method</h4>We performed a single-centre observational cohort study ...[more]
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Project description:BACKGROUND:Critical illness has detrimental effects on the diaphragm, but the impact of critical illness on other major muscles of the respiratory pump has been largely neglected. This study aimed to determine the impact of critical illness on the most important muscles of the respiratory muscle pump, especially on the expiratory muscles in children during mechanical ventilation. In addition, the correlation between changes in thickness of the expiratory muscles and the diaphragm was assessed. METHODS:This longitudinal observational cohort study performed at a tertiary pediatric intensive care unit included 34 mechanical ventilated children (>?1 month-?<?18 years). Thickness of the diaphragm and expiratory muscles (obliquus interna, obliquus externa, transversus abdominis and rectus abdominis) was assessed daily using ultrasound. Contractile activity was estimated from muscle thickening fraction during the respiratory cycle. RESULTS:Over the first 4 days, both diaphragm and expiratory muscles thickness decreased (>?10%) in 44% of the children. Diaphragm and expiratory muscle thickness increased (>?10%) in 26% and 20% of the children, respectively. No correlation was found between contractile activity of the muscles and the development of atrophy. Furthermore, no correlation was found between changes in thickness of the diaphragm and the expiratory muscles (P?=?0.537). Decrease in expiratory muscle thickness was significantly higher in patients failing extubation compared to successful extubation (-?34% vs -?4%, P?=?0.014). CONCLUSIONS:Changes in diaphragm and expiratory muscles thickness develop rapidly after the initiation of mechanical ventilation. Changes in thickness of the diaphragm and expiratory muscles were not significantly correlated. These data provide a unique insight in the effects of critical illness on the respiratory muscle pump in children.
| S-EPMC7450159 | biostudies-literature
Project description:PURPOSE:To evaluate the effect of the positioning from the supine position (SP) to the prone position (PP) on the diaphragm activity in ventilated patients; using the ultrasound (US) imaging. METHODS:A cross-sectional comparative study before/after PP was conducted on 40 ICU patients over 18 years who received invasive ventilation (IV) for at least 48 h. The considered ventilator modes were: assisted control volume with a low trigger flow (between -?2 and 2 L/mn) and pressure support mode. US diaphragmatic assessments were performed at SP and at 60 min of PP. Both End-inspiratory and End-expiratory diameters (EID/EED) were taken at 3 levels of axillary lines and determined by the average values of multiple measures. Diaphragmatic thickening fraction (DTF) was calculated as: DTF?=?(EID?-?EED/EED)?×?100. Pairing and ANOVA tests were used for comparisons. RESULTS:Forty ventilated patients (42 years of median age) at 4 days [2-7] of median duration of ventilation were examined during the two positions: SP versus PP. EID decreased from the SP to the PP (2.8 mm in SP vs. 2.4 mm in PP, p?=?0.001). No difference was showed regarding the expiratory thickness. Overall, DTF didn't change in PP (37.4 vs. 42.05%, p?=?0.36). When the patient was placed in PP, the best DTF value was showed at the posterior part of diaphragm (posterior: 45%, median: 31% and anterior: 38%, p?=?0.049). CONCLUSION:The ventral placement in ventilated patients reduced end-inspiratory diameter and tended to decrease DTF. In PP, the best contractile activity was detected at the posterior region of diaphragm.
| S-EPMC7459156 | biostudies-literature
Project description:BackgroundDiaphragm dysfunction is highly prevalent in mechanically ventilated patients. Recent work showed that changes in diaphragm shear modulus (ΔSMdi) assessed using ultrasound shear wave elastography (SWE) are strongly related to changes in Pdi (ΔPdi) in healthy subjects. The aims of this study were to investigate the relationship between ΔSMdi and ΔPdi in mechanically ventilated patients, and whether ΔSMdi is responsive to change in respiratory load when varying the ventilator settings.MethodsA prospective, monocentric study was conducted in a 15-bed ICU. Patients were included if they met the readiness-to-wean criteria. Pdi was continuously monitored using a double-balloon feeding catheter orally introduced. The zone of apposition of the right hemidiaphragm was imaged using a linear transducer (SL10-2, Aixplorer, Supersonic Imagine, France). Ultrasound recordings were performed under various pressure support settings and during a spontaneous breathing trial (SBT). A breath-by-breath analysis was performed, allowing the direct comparison between ΔPdi and ΔSMdi. Pearson's correlation coefficients (r) were used to investigate within-individual relationships between variables, and repeated measure correlations (R) were used for determining overall relationships between variables. Linear mixed models were used to compare breathing indices across the conditions of ventilation.ResultsThirty patients were included and 930 respiratory cycles were analyzed. Twenty-five were considered for the analysis. A significant correlation was found between ΔPdi and ΔSMdi (R = 0.45, 95% CIs [0.35 0.54], p < 0.001). Individual correlation displays a significant correlation in 8 patients out of 25 (r = 0.55-0.86, all p < 0.05, versus r = - 0.43-0.52, all p > 0.06). Changing the condition of ventilation similarly affected ΔPdi and ΔSMdi. Patients in which ΔPdi-ΔSMdi correlation was non-significant had a faster respiratory rate as compared to that of patient with a significant ΔPdi-ΔSMdi relationship (median (Q1-Q3), 25 (18-33) vs. 21 (15-26) breaths.min-1, respectively).ConclusionsWe demonstrate that ultrasound SWE may be a promising surrogate to Pdi in mechanically ventilated patients. Respiratory rate appears to negatively impact SMdi measurement. Technological developments are needed to generalize this method in tachypneic patients.Trial registrationNCT03832231 .
| S-EPMC7695240 | biostudies-literature
Project description:IntroductionStudies indicate that mechanically ventilated patients develop significant diaphragm muscle weakness, but the etiology of weakness and its clinical impact remain incompletely understood. We assessed diaphragm strength in mechanically ventilated medical ICU patients, correlated the development of diaphragm weakness with multiple clinical parameters, and examined the relationship between the level of diaphragm weakness and patient outcomes.MethodsTransdiaphragmatic twitch pressure (PdiTw) in response to bilateral magnetic stimulation of the phrenic nerves was measured. Diaphragm weakness was correlated with the presence of infection, blood urea nitrogen, albumin, and glucose levels. The relationship of diaphragm strength to patient outcomes, including mortality and the duration of mechanical ventilation for successfully weaned patients, was also assessed.ResultsWe found that infection is a major risk factor for diaphragm weakness in mechanically ventilated medical ICU patients. Outcomes for patients with severe diaphragm weakness (PdiTw<10 cmH2O) were poor, with a markedly increased mortality (49%) compared to patients with PdiTw?10 cmH2O (7% mortality, P=0.022). In addition, survivors with PdiTw<10 cmH2O required a significantly longer duration of mechanical ventilation (12.3±1.7 days) than those with PdiTw?10 cmH2O (5.5±2.0 days, P=0.016).ConclusionsInfection is a major cause of severe diaphragm weakness in mechanically ventilated patients. Moreover, diaphragm weakness is an important determinant of poor outcomes in this patient population.
| S-EPMC3840677 | biostudies-literature
Project description:BACKGROUND:Atelectasis is a common finding in mechanically ventilated children with healthy lungs. This lung collapse cannot be overcome using standard levels of positive end-expiratory pressure (PEEP) and thus for only individualized lung recruitment maneuvers lead to satisfactory therapeutic results. In this short communication, we demonstrate by lung ultrasound images (LUS) the effect of a postural recruitment maneuver (P-RM, i.e., a ventilatory strategy aimed at reaerating atelectasis by changing body position under constant ventilation). RESULTS:Data was collected in the operating room of the Hospital Privado de Comunidad, Mar del Plata, Argentina. Three anesthetized children undergoing mechanical ventilation at constant settings were sequentially subjected to the following two maneuvers: (1) PEEP trial in the supine position PEEP was increased to 10 cmH2O for 3 min and then decreased to back to baseline. (2) P-RM patient position was changed from supine to the left and then to the right lateral position for 90 s each before returning to supine. The total P-RM procedure took approximately 3 min. LUS in the supine position showed similar atelectasis before and after the PEEP trial. Contrarily, atelectasis disappeared in the non-dependent lung when patients were placed in the lateral positions. Both lungs remained atelectasis free even after returning to the supine position. CONCLUSIONS:We provide LUS images that illustrate the concept and effects of postural recruitment in children. This maneuver has the advantage of achieving recruitment effects without the need to elevate airways pressures.
| S-EPMC5640559 | biostudies-literature
Project description:Background:Diaphragm atrophy is observed in mechanically ventilated patients. However, the atrophy is not investigated in other respiratory muscles. Therefore, we conducted a two-center prospective observational study to evaluate changes in diaphragm and intercostal muscle thickness in mechanically ventilated patients. Methods:Consecutive adult patients who were expected to be mechanically ventilated longer than 48?h in the ICU were enrolled. Diaphragm and intercostal muscle thickness were measured on days 1, 3, 5, and 7 with ultrasonography. The primary outcome was the direction of change in muscle thickness, and the secondary outcomes were the relationship of changes in muscle thickness with patient characteristics. Results:Eighty patients (54 males and 26 females; mean age, 68 ± 14?years) were enrolled. Diaphragm muscle thickness decreased, increased, and remained unchanged in 50 (63%), 15 (19%), and 15 (19%) patients, respectively. Intercostal muscle thickness decreased, increased, and remained unchanged in 48 (60%), 15 (19%), and 17 (21%) patients, respectively. Decreased diaphragm or intercostal muscle thickness was associated with prolonged mechanical ventilation (median difference (MD), 3?days; 95% CI (confidence interval), 1-7 and MD, 3?days; 95% CI, 1-7, respectively) and length of ICU stay (MD, 3?days; 95% CI, 1-7 and MD, 3?days; 95% CI, 1-7, respectively) compared with the unchanged group. After adjusting for sex, age, and APACHE II score, they were still associated with prolonged mechanical ventilation (hazard ratio (HR), 4.19; 95% CI, 2.14-7.93 and HR, 2.87; 95% CI, 1.53-5.21, respectively) and length of ICU stay (HR, 3.44; 95% CI, 1.77-6.45 and HR, 2.58; 95% CI, 1.39-4.63, respectively) compared with the unchanged group. Conclusions:Decreased diaphragm and intercostal muscle thickness were frequently seen in patients under mechanical ventilation. They were associated with prolonged mechanical ventilation and length of ICU stay. Trial registration:UMIN000031316. Registered on 15 February 2018.
| S-EPMC6886193 | biostudies-literature
Project description:BackgroundAcute increases in muscle sonographic echodensity reflect muscle injury. Diaphragm echodensity has not been measured in mechanically ventilated patients. We undertook to develop a technique to characterize changes in diaphragm echodensity during mechanical ventilation and to assess whether these changes are correlated with prolonged mechanical ventilation.MethodsDiaphragm ultrasound images were prospectively collected in mechanically ventilated patients and in 10 young healthy subjects. Echodensity was quantified based on the right-skewed distribution of grayscale values (50th percentile, ED50; 85th percentile, ED85). Intra- and inter-analyzer measurement reproducibility was determined. Outcomes recorded included duration of ventilation and ICU complications (including reintubation, tracheostomy, prolonged ventilation, or death).ResultsEchodensity measurements were obtained serially in 34 patients comprising a total of 104 images. Baseline (admission) diaphragm ED85 was increased in mechanically ventilated patients compared to younger healthy subjects (median 56, interquartile range (IQR) 42-84, vs. 39, IQR 36-52, p = 0.04). Patients with an initial increase in median echodensity over time (≥ + 10 in ED50 from baseline) had fewer ventilator-free days to day 60 (n = 13, median 46, IQR 0-52) compared to patients without this increase (n = 21, median 53 days, IQR 49-56, unadjusted p = 0.03). Both decreases and increases in diaphragm thickness during mechanical ventilation were associated with increases in ED50 over time (adjusted p = 0.03, conditional R2 = 0.80) and the association between increase in ED50 and outcomes persisted after adjusting for changes in diaphragm thickness.ConclusionsMany patients exhibit increased diaphragm echodensity at the outset of mechanical ventilation. Increases in diaphragm echodensity during the early course of mechanical ventilation are associated with prolonged mechanical ventilation. Both decreases and increases in diaphragm thickness during mechanical ventilation are associated with increased echodensity.
| S-EPMC7884870 | biostudies-literature
Project description:BackgroundDiaphragm dysfunction develops frequently in ventilated intensive care unit (ICU) patients. Both disuse atrophy (ventilator over-assist) and high respiratory muscle effort (ventilator under-assist) seem to be involved. A strong rationale exists to monitor diaphragm effort and titrate support to maintain respiratory muscle activity within physiological limits. Diaphragm electromyography is used to quantify breathing effort and has been correlated with transdiaphragmatic pressure and esophageal pressure. The neuromuscular efficiency index (NME) can be used to estimate inspiratory effort, however its repeatability has not been investigated yet. Our goal is to evaluate NME repeatability during an end-expiratory occlusion (NMEoccl) and its use to estimate the pressure generated by the inspiratory muscles (Pmus).MethodsThis is a prospective cohort study, performed in a medical-surgical ICU. A total of 31 adult patients were included, all ventilated in neurally adjusted ventilator assist (NAVA) mode with an electrical activity of the diaphragm (EAdi) catheter in situ. At four time points within 72 h five repeated end-expiratory occlusion maneuvers were performed. NMEoccl was calculated by delta airway pressure (?Paw)/?EAdi and was used to estimate Pmus. The repeatability coefficient (RC) was calculated to investigate the NMEoccl variability.ResultsA total number of 459 maneuvers were obtained. At time T?=?0 mean NMEoccl was 1.22?±?0.86 cmH2O/?V with a RC of 82.6%. This implies that when NMEoccl is 1.22 cmH2O/?V, it is expected with a probability of 95% that the subsequent measured NMEoccl will be between 2.22 and 0.22 cmH2O/?V. Additional EAdi waveform analysis to correct for non-physiological appearing waveforms, did not improve NMEoccl variability. Selecting three out of five occlusions with the lowest variability reduced the RC to 29.8%.ConclusionsRepeated measurements of NMEoccl exhibit high variability, limiting the ability of a single NMEoccl maneuver to estimate neuromuscular efficiency and therefore the pressure generated by the inspiratory muscles based on EAdi.
| S-EPMC6161422 | biostudies-literature
Project description:PurposeDiaphragm weakness induced by mechanical ventilation may contribute to difficult weaning from the ventilator. For optimal force generation the muscle proteins myosin and titin are indispensable. The present study investigated if myosin and titin loss or dysfunction are involved in mechanical ventilation-induced diaphragm weakness.MethodsMale Wistar rats were either assigned to a control group (n = 10) or submitted to 18 h of mechanical ventilation (MV, n = 10). At the end of the experiment, diaphragm and soleus muscle were excised for functional and biochemical analysis.ResultsMaximal specific active force generation of muscle fibers isolated from the diaphragm of MV rats was lower than controls (128 ± 9 vs. 165 ± 13 mN/mm(2), p = 0.02) and was accompanied by a proportional reduction of myosin heavy chain concentration in these fibers. Passive force generation upon stretch was significantly reduced in diaphragm fibers from MV rats by ca. 35%. Yet, titin content was not significantly different between control and MV diaphragm. In vitro pre-incubation with phosphatase-1 decreased passive force generation upon stretch in diaphragm fibers from control, but not from MV rats. Mechanical ventilation did not affect active or passive force generation in the soleus muscle.ConclusionsMechanical ventilation leads to impaired diaphragm fiber active force-generating capacity and passive force generation upon stretch. Loss of myosin contributes to reduced active force generation, whereas reduced passive force generation is likely to result from a decreased phosphorylation status of titin. These impairments were not discernable in the soleus muscle of 18 h mechanically ventilated rats.
| S-EPMC3308006 | biostudies-literature
Project description:BackgroundDiaphragm paresis is common after cardiac surgery and may delay the weaning from the ventilator. Our objective was to evaluate diaphragm thickening during weaning and secondly the muscle thickness as a marker of myotrauma.MethodsPatients undergoing elective cardiac surgery were prospectively included. Ultrasonic index of right hemidiaphragm thickening fraction (TF) was measured as a surrogate criterion of work of breathing. A TF < 20% was defined as a low diaphragm thickening. Measurements of TF were performed during three periods to study diaphragm thickening evolution defined by the difference between two consecutive time line point: preoperative (D - 1), during a spontaneous breathing trial (SBT) in the intensive care unit and postoperative (D + 1). We studied three patterns of diaphragm thickness at end expiration evolution from D - 1 to D + 1: > 10% decrease, stability and > 10% increase. Demographical data, length of surgery, type of surgery, ICU length of stay (LOS) and extubation failure were collected.ResultsOf the 100 consecutively included patients, 75 patients had a low diaphragm thickening during SBT. Compared to TF values at D - 1 (36% ± 18), TF was reduced during SBT (17% ± 14) and D + 1 (12% ± 11) (P < 0.0001). Thickness and TF did not change according to the type of surgery or cooling method. TF at SBT was correlated to the length of surgery (both r = - 0.4; P < 0.0001). Diaphragm thickness as continuous variable did not change over time. Twenty-eight patients (42%) had a > 10% decrease thickness, 19 patients (29%) stability and 19 patients (28%) in > 10% increase, and this thickness evolution pattern was associated with: a longer LOS 3 days [2-5] versus 2 days [2-4] and 2 days [2], respectively (ANOVA P = 0.046), and diaphragm thickening evolution (ANOVA P = 0.02). Two patients experience extubation failure.ConclusionThese findings indicate that diaphragm thickening is frequently decreased after elective cardiac surgery without impact on respiratory outcome, whereas an altered thickness pattern was associated with a longer length of stay in the ICU. Contractile activity influenced thickness evolution. Trial registry number ClinicalTrial.gov ID NCT02208479.
| S-EPMC6478777 | biostudies-literature