Diaphragmatic Thickening Fraction Research Articles

Effect of Individualized PEEP Guided by Driving Pressure on Diaphragm Function in Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer: A Randomized Controlled Trial.

BACKGROUND The concept of driving pressure (ΔP) has been established to optimize mechanical ventilation-induced lung injury. However, little is known about the specific effects of setting individualized positive end-expiratory pressure (PEEP) with driving pressure guidance on patient diaphragm function. MATERIAL AND METHODS Ninety patients were randomized into 3 groups, with PEEP set to 0 in group C; 5 cmH₂O in group F; and individualized PEEP in group I, based on esophageal manometry. Diaphragm ultrasound was performed in the supine position at 6 consecutive time points from T0-T5: diaphragm excursion, end-expiratory diaphragm thickness (Tdi-ee), and diaphragm thickening fraction (DTF) were measured. Primary indicators included diaphragm excursion, Tdi-ee, and DTF at T0-T5, and the correlation between postoperative DTF and ΔP. Secondary indicators included respiratory mechanics, hemodynamic changes at intraoperative d0-d4 time points, and postoperative clinical pulmonary infection scores. RESULTS (1) Diaphragm function parameters reached the lowest point at T1 in all groups (P<0.001). (2) Compared with group C, diaphragm excursion decreased, Tdi-ee increased, and DTF was lower in groups I and F at T1-T5, with significant differences (P<0.05), but the differences between groups I and F were not significant (P>0.05). (3) DTF was significantly and positively correlated with mean intraoperative ΔP in each group at T3, and the correlation was stronger at higher levels of ΔP. CONCLUSIONS Individualized PEEP, achieved by esophageal manometry, minimizes diaphragmatic injury caused by mechanical ventilation based on lung protection, but its protection of the diaphragm during laparoscopic surgery is not superior to that of conventional ventilation strategies.

Combined cardiac, lung, and diaphragm ultrasound for predicting weaning failure during spontaneous breathing trial

BackgroundWeaning from invasive mechanical ventilation (MV) is a complex and challenging process that involves multiple pathophysiological mechanisms. A combined ultrasound evaluation of the heart, lungs, and diaphragm during the weaning phase can help to identify risk factors and underlying mechanisms for weaning failure. This study aimed to investigate the accuracy of lung ultrasound (LUS), transthoracic echocardiography (TTE), and diaphragm ultrasound for predicting weaning failure in critically ill patients.MethodsPatients undergoing invasive MV for > 48 h and who were readied for their first spontaneous breathing trial (SBT) were studied. Patients were scheduled for a 2-h SBT using low-level pressure support ventilation. LUS and TTE were performed prospectively before and 30 min after starting the SBT, and diaphragm ultrasound was only performed 30 min after starting the SBT. Weaning failure was defined as failure of SBT, re-intubation, or non-invasive ventilation within 48 h.ResultsFifty-one patients were included, of whom 15 experienced weaning failure. During the SBT, the global, anterior, and antero-lateral LUS scores were higher in the failed group than in the successful group. Receiver operating characteristic curve analysis showed that the areas under the curves for diaphragm thickening fraction (DTF) and global and antero-lateral LUS scores during the SBT to predict weaning failure were 0.678, 0.719, and 0.721, respectively. There was no correlation between the LUS scores and the average E/e’ ratio during the SBT. Multivariate analysis identified antero-lateral LUS score > 7 and DTF < 31% during the SBT as independent predictors of weaning failure.ConclusionLUS and diaphragm ultrasound can help to predict weaning failure in patients undergoing an SBT with low-level pressure support. An antero-lateral LUS score > 7 and DTF < 31% during the SBT were associated with weaning failure.Graphical

Lung and diaphragm ultrasound as predictors of successful weaning from nasal continuous positive airway pressure in preterm infants.

Assessment of the utility of lung and diaphragm ultrasound in the prediction of successful weaning from nasal continuous positive airway pressure (NCPAP) in preterm infants. This prospective cohort study was conducted on preterm infants who were considered ready for weaning off NCPAP. Lung and diaphragm ultrasound were performed just before and 3 h after weaning off NCPAP. The primary outcome was to evaluate the accuracy of lung ultrasound (LUS) in predicting successful weaning from NCPAP. Out of 65 enrolled preterm infants, 30 (46.2%) were successfully weaned from NCPAP to room air. The successful weaning group had higher gestational ages, lower incidences of previous invasive mechanical ventilation, and treated hemodynamically significant patent ductus arteriosus before the trial weaning. A LUS score of ≤6, measured before discontinuation of NCPAP, exhibited a predictive sensitivity of 80% and specificity of 75% for successful weaning (Area under the curve (AUC) = 0.865, ≤.001). When the LUS score was assessed 3 h after weaning from NCPAP, a cutoff point of ≤7 predicted successful weaning with a sensitivity and specificity of 90% and 60% respectively (AUC = 0.838, p ≤ .001). The diaphragmatic thickness fraction (DTF) was significantly lower in the successful weaning group. After adjustment for various factors, LUS score remained the only independent predictor of successful weaning. LUS score before weaning from NCPAP has a good sensitivity and specificity for predicting successful weaning from NCPAP in preterm infants. Diaphragmatic excursion and DTF were not good predictors.

The effects of robot-assisted laparoscopic surgery with Trendelenburg position on short-term postoperative respiratory diaphragmatic function

ObjectiveTo study how Pneumoperitoneum under Trendelenburg position for robot-assisted laparoscopic surgery impact the perioperative respiratory parameters, diagrammatic function, etc.MethodsPatients undergoing robot-assisted laparoscopic surgery in the Trendelenburg position and patients undergoing general surgery in the supine position were selected. The subjects were divided into two groups according to the type of surgery: robot-assisted surgery group and general surgery group. ① Respiratory parameters such as lung compliance, oxygenation index, and airway pressure were recorded at 5 min after intubation, 1 and 2 h after pneumoperitoneum. ② Diaphragm excursion (DE) and diaphragm thickening fraction (DTF) were recorded before entering the operating room (T1), immediately after extubation (T2), 10 min after extubation (T3), and upon leaving the postanesthesia care unit (T4). ③ Peripheral venous blood (5 ml) was collected before surgery and 30 min after extubation and was analyzed by enzyme-linked immunosorbent assay to determine the serum concentration of Clara cell secretory protein 16 (CC16) and surfactant protein D (SP-D).Result① Compared with the general surgery group (N = 42), the robot-assisted surgery group (N = 46) presented a significantly higher airway pressure and lower lung compliance during the surgery(P < 0.001). ② In the robot-assisted surgery group, the DE significantly decreased after surgery (P < 0.001), which persisted until patients were discharged from the PACU (P < 0.001), whereas the DTF only showed a transient decrease postoperatively (P < 0.001) and returned to its preoperative levels at discharge (P = 0.115). In the general surgery group, the DE showed a transient decrease after surgery(P = 0.011) which recovered to the preoperative levels at discharge (P = 1). No significant difference in the DTF was observed among T1, T2, T3, and T4. ③ Both the general and robot-assisted surgery reduced the postoperative serum levels of SP-D (P < 0.05), while the robot-assisted surgery increased the postoperative levels of CC16 (P < 0.001).ConclusionRobot-assisted laparoscopic surgery significantly impairs postoperative diaphragm function, which does not recover to preoperative levels at PACU discharge. Elevated levels of serum CC16 after surgery suggest potential lung injury. The adverse effects may be attributed to the prolonged Trendelenburg position and pneumoperitoneum during laparoscopic surgery.

Effects of helium-oxygen mechanical ventilation on inflammatory response of diseased lung segments and diaphragm function in patients with pneumonia

To investigate the clinical effect of helium-oxygen mechanical ventilation on inflammation of the diseased lung segment and diaphragm function in patients with acute respiratory distress syndrome (ARDS) caused by pneumonia who suffered difficulty weaning from mechanical ventilation. A prospective controlled study was conducted. A total of 40 patients with ARDS caused by pneumonia and requiring tracheal intubation with difficulty weaning from mechanical ventilation, admitted to the department of critical care medicine in Pingtan Branch of Fujian Medical University Union Hospital from October 2020 to December 2021 were enrolled. Patients were divided into nitrogen oxygen ventilation group and helium-oxygen ventilation group according to random number table, with 20 cases in each group. The nitrogen oxygen ventilation group was given 60% nitrogen and 40% oxygen ventilation treatment, and the helium-oxygen ventilation group was given 60% helium and 40% oxygen ventilation treatment. Peak airway pressure (Ppeak), plateau airway pressure (Pplat), tidal volume (VT), minute ventilation volume (MV) and pulse oxygen saturation (SpO2) were collected at 0, 1, 2, 3 hours after ventilation treatment. At the same time, the concentrations of inflammatory factors interleukin-6 (IL-6) and C-reactive protein (CRP) in epithelial lining fluid in patients with diseased lung segments were measured before and after ventilation treatment for 3 hours, and the diaphragmatic excursion and the diaphragmatic thickening fraction were measured before and after ventilation treatment for 3 hours. There were no significant differences in gender, age, oxygenation index, serum CRP, serum procalcitonin (PCT), body temperature, serum creatinine (SCr), alanine aminotransferase (ALT), fasting blood glucose (FPG), hemoglobin (Hb), and basic heart and lung diseases between the two groups. Under the condition that VT and SpO2 are relatively unchanged, the airway pressure in helium-oxygen ventilation group decreased significantly after 1 hour of ventilation [Ppeak (cmH2O, 1 cmH2O≈0.098 kPa): 22.80±4.47 vs. 28.00±5.07, Pplat (cmH2O): 19.15±3.90 vs. 23.20±3.81, both P < 0.05], and the airway pressure in the nitrogen oxygen ventilation group increased significantly after 1 hour [Ppeak (cmH2O): 22.35±2.13 vs. 19.75±1.94, Pplat (cmH2O): 18.50±1.70 vs. 16.50±1.88, both P < 0.05]. There were no significant differences in CRP and IL-6 levels in epithelial lining fluid in the diseased lung segment before and after ventilation in the nitrogen oxygen ventilation group, while the levels of these indexes in the helium-oxygen ventilation group after ventilation were significantly lower than those before ventilation, and significantly lower than those in the nitrogen oxygen ventilation group [CRP (mg/L): 10.15 (6.39, 15.84) vs. 16.10 (11.63, 18.66), IL-6 (μg/L): 1.15 (0.78, 1.86) vs. 2.67 (1.67, 4.85), both P < 0.05]. There were no statistically significant differences in the diaphragmatic excursion and the diaphragmatic thickening fraction before and after ventilation in the nitrogen oxygen ventilation group, while the above indexes in the helium-oxygen ventilation group were significantly higher than those before ventilation, and were significantly higher than those in the nitrogen oxygen ventilation group [diaphragmatic excursion (cm): 1.93 (1.69, 2.20) vs. 1.34 (1.22, 1.83), diaphragmatic thickening fraction: (48.22±8.61)% vs. (33.29±11.04)%, both P < 0.05]. Helium-oxygen ventilation can reduce the airway pressure of patients with mechanical ventilation, alleviate the inflammatory response of lung segment, improve the function of respiratory muscle, and is expected to be an important treatment for severe lung rehabilitation.

Ultrasonographic changes and impact factors of diaphragmatic function in patients with obstructive sleep apnea-hypopnea syndrome.

Diaphragmatic impairment has been reported in obstructive sleep apnea-hypopnea syndrome (OSAHS) patients. However, the risk factors of diaphragmatic dysfunction are unclear. This study was conducted to evaluate the diaphragmatic function and to investigate impact factors of ultrasonographic changes of the diaphragm in OSAHS patients. This cross-sectional study recruited 150 snoring patients. All patients were divided into the control group (AHI < 5/h, n = 20), the mild-to-moderate OSAHS group (5/h ≤ AHI ≤ 30/h, n = 61), and the severe OSAHS group (AHI > 30/h, n = 69). Diaphragmatic thickness at function residual capacity (TFRC) and total lung capacity (TTLC) were measured by two-dimensional ultrasound, and the diaphragmatic excursion during tidal and deep breath was measured by M-mode ultrasound. The diaphragmatic thickening fraction (TF) was calculated. Spearman analysis and multiple linear stepwise regression analysis were conducted to analyze the impact factors of diaphragmatic function. TFRC in the control group, mild-to-moderate OSAHS group, and severe OSAHS group was 1.23 (1.10, 1.39) mm, 1.60 (1.43, 1.85) mm, and 1.90 (1.70, 2.25) mm; TTLC was 2.75 (2.53, 2.93) mm, 3.25 (2.90, 3.55) mm, and 3.60 (3.33, 3.90) mm, and TF was 119.23% (102.94, 155.97), 96.55% (74.34, 119.11), and 85.29% (60.68,101.22). There were across-group significant differences in TFRC, TTLC, and TF (P < 0.05). The oxygen desaturation index was the influencing factor of TFRC, TTLC, and TF (P < 0.05). The diaphragm is thickened and diaphragmatic contractility is decreased in OSAHS patients. Nocturnal intermittent hypoxia is a risk factor for diaphragmatic hypertrophy and impaired diaphragmatic contractility.

Predictive values of ultrasonic diaphragm thickening fraction combined with integrative weaning index in weaning patients with mechanical ventilation: a retrospective study

ObjectiveWe aimed to explore the predictive values of ultrasonic diaphragm thickening fraction (DTF) combined with integrative weaning index (IWI) in weaning patients with mechanical ventilation.MethodsPatients with mechanical ventilation who received oral endotracheal intubation from September 2020 to September 2021 were included in this retrospective study. Before the start of the spontaneous breathing test (SBT), IWI was calculated according to the blood gas analysis parameters and parameters read in volume control mode. After the start of SBT, DTF was calculated according to the end-expiratory thickness and end-inspiratory thickness of the right diaphragm. The receiver operating curve (ROC) was used to evaluate the predictive value of DTF and IWI for successful weaning, and the sensitivity and specificity were calculated according to the best critical value.ResultsThe sensitivity, specificity, and best cutoff value of DTF to predict successful weaning was 0.772, 0.727, and 0.293, respectively, and the area under the curve (AUC) was 0.72 (95%CI 0.59–0.86, p = 0.003). The sensitivity, specificity, and best cutoff value of IWI to predict successful weaning was 0.614, 0.909, 53.00, respectively, and AUC was 0.82 (95%CI 0.72–0.91, p < 0.001). The sensitivity, specificity, and best cutoff value of the combination of DTF and IWI to predict successful weaning was 0.614, 0.909, 17.848, respectively, and AUC was 0.84 (95%CI 0.75–0.93, p < 0.001).ConclusionDTF and IWI can guide the selection of weaning, while DTF combined with IWI can improve the effect of weaning prediction and provide support for patients’ weaning safety.

The effect of high-flow oxygen via tracheostomy on respiratory pattern and diaphragmatic function in patients with prolonged mechanical ventilation: A randomized, physiological, crossover study

BackgroundCompared to conventional oxygen devices, high-flow oxygen treatment (HFOT) through the nasal cannulae has demonstrated clinical benefits. Limited data exist on whether such effects are also present in HFOT through tracheostomy. Hence, we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation. MethodsA randomized, crossover, physiological study was conducted in our ICU between December 2020 and April 2021, in patients with tracheostomy and prolonged mechanical ventilation. The patients underwent a 30-min spontaneous breathing trial (SBT) and received oxygen either via T-piece or by HFOT through tracheostomy, followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner. At the start and end of each session, blood gasses, breathing frequency (f), and tidal volume (VT) via a Wright's spirometer were measured, along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction, which expressed the inspiratory muscle effort. ResultsEleven patients were enrolled in whom 19 sessions were uneventfully completed; eight patients were studied twice on two different days with alternate sessions; and three patients were studied once. Patients were randomly assigned to start the SBT with a T-piece (n=10 sessions) or with HFOT (n=9 sessions). With HFOT, VT and minute ventilation (VE) significantly increased during SBT (from [465±119] mL to [549±134] mL, P <0.001 and from [12.4±4.3] L/min to [13.1±4.2] L/min, P <0.05, respectively), but they did not change significantly during SBT with T-piece (from [495±132] mL to [461±123] mL and from [12.8±4.4] mL to [12.0±4.4] mL, respectively); f/VT decreased during HFOT (from [64±31] breaths/(min∙L) to [49±24] breaths/(min∙L), P <0.001), but it did not change significantly during SBT with T-piece (from [59±28] breaths/(min∙L) to [64±33] breaths/(min∙L)); partial pressure of arterial oxygen increased during HFOT (from [99±39] mmHg to [132±48] mmHg, P <0.001), but it decreased during SBT with T-piece (from [124±50] mmHg to [83±22] mmHg, P <0.01). In addition, with HFOT, diaphragmatic excursion increased (from [12.9±3.3] mm to [15.7±4.4] mm, P <0.001), but it did not change significantly during SBT with T-piece (from [13.4±3.3] mm to [13.6±3.3] mm). The diaphragmatic thickening fraction did not change during SBT either with T-piece or with HFOT. ConclusionIn patients with prolonged mechanical ventilation, HFOT through tracheostomy compared with T-piece improves ventilation, pattern of breathing, and oxygenation without increasing the inspiratory muscle effort. Trial RegistrationClinicaltrials.gov ldentifer: NCT04758910.

Mask Continuous Positive Airway Pressure Increases Diaphragm Thickening Fraction in Healthy Subjects

Introduction: The most widespread treatment for obstructive sleep apnoea and obesity hypoventilation syndrome is continuous positive airway pressure (CPAP). The addition of inspiratory support is a potential alternative. This is a physiological study to determine the effect of CPAP and inspiratory support pressure on respiratory effort measured by diaphragm thickening fraction (DTF) in healthy volunteers. Methods: DTF was measured in spontaneously breathing, healthy volunteers during 4 phases: (I) without connection to a ventilator, (II) on a ventilator without any applied pressures, (III) with a CPAP of 5 cmH₂O, and (IV) with an additional inspiratory support pressure of 5 cmH₂O. Results: Twenty-nine individuals agreed to participate. DTF was similar during the first two phases (32 ± 13% and 35 ± 22%). A considerable increase in DTF to 51 ± 21% was noted in phase III. The introduction of inspiratory support pressure during phase IV led to a reduction in DTF back to 36 ± 23% (p < 0.001). Tidal volume and minute ventilation were both slightly higher in phase IV compared to phase III. Conclusion: CPAP without inspiratory support pressure increases respiratory effort measured by DTF in healthy subjects. Further research is required to investigate this phenomenon in a clinical setting.

Use of a combination of diaphragmatic ultrasound and muscle relaxation monitoring in predicting post-extubation adverse respiratory events among elderly patients in an anesthesia intensive care unit

ObjectiveThe purpose of this study was to examine the feasibility of using a combination of diaphragmatic ultrasound and muscle relaxation monitoring in predicting adverse respiratory events after extubation among elderly patients in an anesthetic intensive care unit (AICU).MethodsThe study participants were 120 elderly patients who were in the AICU after laparoscopic radical resection for colorectal cancer. Based on whether there were critical respiratory events (CREs) after extubation, they were divided into the adverse event group and the non-adverse event group. We used logistic regression to identify factors influencing the occurrence of CREs post-extubation in elderly patients. Using the receiver operating characteristic (ROC) curve, we analyzed the value of each indicator in predicting CREs post-extubation.ResultsWe included 109 patients in the final analysis. In the adverse event group (n = 19), the age, proportion of females, and proportion of preoperative respiratory diseases were higher than in the non-adverse event group (n = 90). The muscle relaxation value, quiet breathing diaphragmatic excursion during extubation (DE-QB), deep breathing diaphragmatic excursion during extubation (DE-DB), and deep breathing diaphragmatic thickening fraction during extubation (DTF-DB) of patients in the adverse event group were significantly lower than those in the non-adverse event group (P < 0.05). Using binary logistic regression analysis, we identified muscle relaxation value, DE-DB, and DTF-DB during extubation as significant predictors of CREs post-extubation in elderly patients (P < 0.05). The area under the curve (AUC) of the combination of the muscle relaxation value, DE-DB, and DTF-DB during extubation for predicting CREs after extubation in elderly patients was 0.949, which was higher than that of any single indicator.ConclusionThe combination of diaphragmatic ultrasound and muscle relaxation monitoring was more accurate in predicting CREs post-extubation among elderly patients in the AICU.

The role of ultrasound in predicting non-invasive ventilation outcomes: a systematic review.

To systematically review and compare ultrasonographic methods and their utility in predicting non-invasive ventilation (NIV) outcomes. A systematic review was performed using the PubMed, Medline, Embase, and Cochrane databases from January 2015 to March 2023. The search terms included the following: ultrasound, diaphragm, lung, prediction, non-invasive, ventilation, and outcomes. The inclusion criteria were prospective cohort studies on adult patients requiring non-invasive ventilation in the emergency department or inpatient setting. Fifteen studies were analyzed, which comprised of 1,307 patients (n = 942 for lung ultrasound score studies; n = 365 patients for diaphragm dysfunction studies). Lung ultrasound scores (LUS) greater than 18 were associated with NIV failure with a sensitivity 62-90.5% and specificity 60-91.9%. Similarly, a diaphragm thickening fraction (DTF) of less than 20% was also associated with NIV failure with a sensitivity 80-84.6% and specificity 76.3-91.5%. Predicting NIV failure can be difficult by routine initial clinical impression and diagnostic work up. This systematic review emphasizes the importance of using lung and diaphragm ultrasound, in particular the lung ultrasound score and diaphragm thickening fraction respectively, to accurately predict NIV failure, including the need for ICU-level of care, requiring invasive mechanical ventilation, and resulting in higher rates of mortality.

Predictive value of diaphragmatic thickening fraction combined with MRC score for the outcome of weaning from mechanical ventilation in ICU-acquired weakness patients

To explore the predictive value of diaphragmatic thickening fraction (DTF) combined with Medical Research Council-score (MRC score) on the outcome of weaning from mechanical ventilation in ICU-acquired weakness (ICU-AW) patients. A retrospective case-control study was conducted. The clinical data of mechanically ventilated patients with an MRC score of less than 48 admitted to the department of critical care medicine of the First Affiliated Hospital of Wannan Medical College from January 2022 to March 2023 were collected, including general information, ultrasound indicators, MRC scores, main clinical outcomes, and weaning outcomes. Patients were divided into successful weaning group and failed weaning group according to whether the patient could maintain effective autonomous breathing for at least 48 hours without using an invasive or non-invasive ventilator. The clinical data of the two groups were compared. Receiver operator characteristic curve (ROC curve) was plotted to analyze the predictive value of DTF and MRC score alone or in combination for successful weaning of patients. A total of 87 patients were enrolled, of which 58 were successful weaning and 29 were failed weaning. There were no statistically significant differences in general data such as gender, age, underlying disease, heart rate (HR), mean arterial pressure (MAP), pH value, blood lactic acid (Lac), oxygenation index (PaO2/FiO2), and severity scores between the two groups. Compared with the failed weaning group, the DTF and MRC scores of patients in the successful weaning group were significantly increased [DTF: (26.02±2.68)% vs. (22.79±5.40)%, MRC score: 38.90±2.78 vs. 33.24±3.78, both P < 0.05]. The duration of mechanical ventilation and the length of ICU stay of patients in the successful weaning group were significantly shorter than those in the failed weaning group [duration of mechanical ventilation (hours): 102.21±32.60 vs. 113.14±41.34, length of ICU stay (days): 6.48±2.18 vs. 10.11±4.01, both P < 0.05], and the re-intubation rate and ICU hospitalization cost were significantly lowered [re-intubation rate: 6.90% (4/58) vs. 27.59% (8/29), ICU hospitalization cost (10 000 RMB): 4.99±0.87 vs. 7.85±2.45, both P < 0.05]. ROC curve analysis showed that the area under the ROC curve (AUC) of DTF and MRC score for predicting successful weaning in ICU-AW mechanical ventilation patients was 0.839 [95% confidence interval (95%CI) was 0.746-0.931] and 0.799 (95%CI was 0.701-0.899), respectively. Using DTF ≥ 25.01% as the optimal cut-off value to predict successful weaning, the sensitivity was 82.76%, and the specificity was 72.41%. Predicting successful weaning based on an optimal cut-off value of MRC score of ≥ 35.50 had a sensitivity of 79.31% and a specificity of 70.69%. Based on the DTF ≥ 25.01% combined with MRC score ≥ 35.50, it was predicted that the weaning would be successful, with an AUC of 0.887 (95%CI was 0.812-0.962), sensitivity increased to 89.70%, and specificity increased to 79.30%. The DTF and MRC score have good guiding value for the selection of weaning timing and predicting the weaning outcomes in ICU-AW patients. Compared with independent DTF and MRC score, the combination of DTF and MRC score improves the predictive value of successful weaning in ICU-AW patients.

Spinal cord perfusion pressure correlates with breathing function in patients with acute, cervical traumatic spinal cord injuries: an observational study

ObjectiveThis study aims to determine the relationship between spinal cord perfusion pressure (SCPP) and breathing function in patients with acute cervical traumatic spinal cord injuries.MethodsWe included 8 participants without cervical TSCI plus 13 patients with cervical traumatic spinal cord injuries, American Spinal Injury Association Impairment Scale grades A–C. In the TSCI patients, we monitored intraspinal pressure from the injury site for up to a week and computed the SCPP as mean arterial pressure minus intraspinal pressure. Breathing function was quantified by diaphragmatic electromyography using an EDI (electrical activity of the diaphragm) nasogastric tube as well as by ultrasound of the diaphragm and the intercostal muscles performed when sitting at 20°–30°.ResultsWe analysed 106 ultrasound examinations (total 1370 images/videos) and 198 EDI recordings in the patients with cervical traumatic spinal cord injuries. During quiet breathing, low SCPP (< 60 mmHg) was associated with reduced EDI-peak (measure of inspiratory effort) and EDI-min (measure of the tonic activity of the diaphragm), which increased and then plateaued at SCPP 60–100 mmHg. During quiet and deep breathing, the diaphragmatic thickening fraction (force of diaphragmatic contraction) plotted versus SCPP had an inverted-U relationship, with a peak at SCPP 80–90 mmHg. Diaphragmatic excursion (up and down movement of the diaphragm) during quiet breathing did not correlate with SCPP, but diaphragmatic excursion during deep breathing plotted versus SCPP had an inverse-U relationship with a peak at SCPP 80–90 mmHg. The thickening fraction of the intercostal muscles plotted versus SCPP also had inverted-U relationship, with normal intercostal function at SCPP 80–100 mmHg, but failure of the upper and middle intercostals to contract during inspiration (i.e. abdominal breathing) at SCPP < 80 or > 100 mmHg.ConclusionsAfter acute, cervical traumatic spinal cord injuries, breathing function depends on the SCPP. SCPP 80–90 mmHg correlates with optimum diaphragmatic and intercostal muscle function. Our findings raise the possibility that intervention to maintain SCPP in this range may accelerate ventilator liberation which may reduce stay in the neuro-intensive care unit.

Accuracy of lung and diaphragm ultrasound in predicting infant weaning outcomes: a systematic review and meta-analysis.

Although lung and diaphragm ultrasound are valuable tools for predicting weaning results in adults with MV, their relevance in children is debatable. The goal of this meta-analysis was to determine the predictive value of lung and diaphragm ultrasound in newborn weaning outcomes. For eligible studies, the databases MEDLINE, Web of Science, Cochrane Library, PubMed, and Embase were thoroughly searched. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) method was used to evaluate the study's quality. Results were gathered for sensitivity, specificity, diagnostic odds ratio (DOR), and the area under the curve of summary receiver operating characteristic curves (AUSROC). To investigate the causes of heterogeneity, subgroup analyses and meta-regression were conducted. A total of 11 studies were suitable for inclusion in the meta-analysis, which included 828 patients. The pooled sensitivity and specificity of lung ultrasound (LUS) were 0.88 (95%CI, 0.85-0.90) and 0.81 (95%CI, 0.75-0.87), respectively. The DOR for diaphragmatic excursion (DE) is 13.17 (95%CI, 5.65-30.71). The AUSROC for diaphragm thickening fraction (DTF) is 0.86 (95%CI, 0.82-0.89). The most sensitive and specific method is LUS. The DE and DTF were the key areas where study heterogeneity was evident. Lung ultrasonography is an extremely accurate method for predicting weaning results in MV infants. DTF outperforms DE in terms of diaphragm ultrasound predictive power.

Ultrasound Assessment of Diaphragm Function in Traumatic Brain Injury: A Prospective Observational Study

Abstract Background Prolonged mechanical ventilation is associated with weaning failure in severe TBI patients. Ultrasound is a noninvasive modality for evaluating diaphragm function. On ultrasonography (USG), diaphragm thickness is observed to decrease over time in mechanically ventilated patients. However, little literature exists on the severity of diaphragmatic dysfunction in traumatic brain injury (TBI) patients. This study aimed to observe the changes occurring in diaphragmatic function in mechanically ventilated TBI patients. Methods TBI patients aged 18 to 65 years, requiring mechanical ventilation, were included. USG assessment of diaphragm function was done on days 0, 3, 5 and 7 of neurotrauma intensive care unit (NICU) admission in the supine position, during sedation holiday and spontaneous breathing trial. Measurements were done at end expiration (TE) and at maximal inspiration (TI) using 7- to 13-MHz linear array probe for three consecutive times and then averaged. Thickness fraction was calculated as (TI – TE/TE) × 100. Diaphragmatic excursion (DE) was measured in the M mode using 1- to 5-MHz phased array probe, as maximal height of inspiration. Results Forty patients were evaluated. The mean diaphragmatic thickness fraction (DTF) at days 0, 3, 5, and 7 was 33.58 ± 10.08, 33.4 ± 9.76, 32.32 ± 8.36, and 31.65 ± 8.23, respectively. Change in DTF was statistically significant on day 7 (p = 0.040). The mean DE at days 0, 3, 5, and 7 was 9.61 ± 3.99, 9.02 ± 3.46, 8.87 ± 2.63, 8.56 ± 2.74, respectively. Changes in DE over days 3, 5, and 7 were statistically significant (p &lt; 0.001). The mean DTF was lower on day 3 in patients who were admitted for less than 20 days than those who required hospital admission for more than 20 days (p = 0.044). Conclusion Decrease in DTF and DE over the period of 7 days was observed with a significant decrease occurring on the 7th day following TBI.

Ultrasonographic Evaluation of Diaphragmatic Thickness versus Excursion as a Predictor of Weaning in Mechanically Ventilated Patients

Abstract Background Best predictor of successful extubation after mechanical ventilation is a matter of debate. Objective The aim of this study was to assess the efficiency of diaphragm thickness and/or diaphragm excursion as measured by means of ultrasound as a predictor of extubation in mechanically ventilated patients in ICU. Methods We performed a prospective study on fifty patients who successfully passed spontaneous breathing trial (SBT). During T-tube spontaneous breathing trial (SBT) we evaluated the right hemidiaphragm excursion by using the M mode and diaphragmatic thickness fraction (DTF%) using B mode, and they were classified in to the successful extubation group and the failure group. Primary outcome: defined as weaning failure and requirement of either noninvasive ventilation or mechanical ventilation. Secondary outcome: To investigate possible factors related to weaning failure Results Of the 50 patients in the study, 35 patients were successfully weaned and 15 failed weaning. The mean diaphragmatic thickness fraction with respect to cut-off value was higher in the failure group during SBT whereas the diaphragmatic excursion with respect to cut off value was less in the failure group during SBT while there was increase in both DTF and diaphragmatic excursion with respect to cut off value in the success group. The diaphragmatic excursion cut-off value predictive of weaning was 10 mm with a specificity 78% and sensitivity 82% respectively and the diaphragmatic thickness cut-off value predictive of weaning was 21.5% with a specificity of 71% and sensitivity of 76% respectively. There was negative correlation between diaphragmatic function and duration of mechanical ventilation. Conclusion The diaphragmatic ultrasonography was found to be a promising tool for predicting the extubation outcome for mechanically ventilated patients.

Sonographic assessment of diaphragmatic thickness and excursion to predict CPAP failure in neonates below 34 weeks of gestation: A prospective cohort study.

To evaluate the diagnostic accuracy of sonographic assessment of diaphragmatic dimensions and excursions in predicting Continuous Positive Airway Pressure (CPAP) failure in preterm neonates with respiratory distress. Prospective cohort study among preterm neonates less than 34 weeks of gestation who were hemodynamically stable and either admitted with respiratory distress or who developed respiratory distress shortly after admission to the NICU and having Silverman-Anderson Score (SAS) ≥ 3/10 were included. We performed sonographic assessment of diaphragmatic dimensions and excursions before and one hour ±30 minutes after application of CPAP. 'CPAP failure' was defined as combined outcome of the need of surfactant and/or upgradation of respiratory support within first 72 hours after a trial of CPAP. Clinical parameters and diaphragmatic measurements were compared between CPAP failure and success groups. Of 62 participants, 20 (32%) failed CPAP. On binomial logistic regression (after adjustment for gestational age and birth weight), initial SAS, higher diaphragmatic excursion (both left and right, before and after CPAP application), lower left hemidiaphragm diaphragmatic thickness fraction (DTF) (before CPAP application) and lower right DTF (after CPAP application) were independent predictors of CPAP failure. However, the receiver-operating characteristics curves showed that excursions of right and left hemi-diaphragm both before and after CPAP application, had highest accuracies in predicting CPAP failure (AUC 0.84, 0.80 and 0.86, 0.78, respectively; p < .001). Diaphragmatic excursion can be a useful parameter to predict the failure of CPAP in preterm neonates with respiratory distress.

Effect of neuromuscular electrical stimulation combined with early rehabilitation therapy on mechanically ventilated patients: a prospective randomized controlled study

BackgroundThis study aimed to investigate the effectiveness of neuromuscular electrical stimulation (NMES) blended with early rehabilitation on the diaphragm and skeletal muscle in sufferers on mechanical ventilation (MV).MethodThis is a prospective randomized controlled study. Eighty patients on MV for respiratory failure were divided into a study group (40 cases) and a control group (40 cases) randomly. The study group adopted a treatment method of NMES combined with early rehabilitation and the control group adopted the method of early rehabilitation only. The diaphragmatic excursion (DE), diaphragmatic thickening fraction (DTF), variation of thickness of intercostal muscles (TIM), variation of thickness of rectus abdominis (TRA), and variation of the cross-sectional area of rectus femoris (CSA-RF) were measured to evaluate the therapeutic effect by ultrasound before and after intervention at the first day of MV, the 3rd and 7th day of intervention and the day discharged from ICU.ResultsNo significant difference was found in the general demographic information and ultrasound indicators between the two groups before treatment (all P > 0.05). After treatment, the variation of DTF (0.15 ± 0.05% vs. 0.12 ± 0.04%, P = 0.034) was significantly higher in the study group than that in the control group on the day discharged from ICU. The variation of TRA (0.05 ± 0.09% vs. 0.10 ± 0.11%, P = 0.029) and variation of CSA-RF (0.13 ± 0.07% vs. 0.19 ± 0.08%, P < 0.001) in the study group were significantly lower than that in the control group. The duration of MV in the study group was significantly shorter than that in the control group [109.5 (88.0, 213.0) hours vs. 189.5 (131.5, 343.5) hours, P = 0.023]. The study group had better muscle strength score than the control group at discharge (52.20 ± 11.70 vs. 44.10 ± 15.70, P = 0.011).ConclusionNMES combined with early rehabilitation therapy is beneficial in reducing muscle atrophy and improving muscle strength in mechanically ventilated patients. This treatment approach may provide a new option for patients to choose a rehabilitation program; however, more research is needed to fully evaluate the effectiveness of this treatment option.

Impact of pressure-targeted modes of ventilation on diaphragmatic function as assessed using ultrasonography in critically ill patients with cerebral insult: a randomized clinical trial

BackgroundMechanical ventilation causes diaphragmatic atrophy and reduces diaphragmatic efficiency. Patients with diaphragmatic dysfunction have longer mechanical ventilation durations and intensive care unit stay. There is currently a scarcity of data on the effect of different modes of mechanical ventilation on diaphragmatic function and ultrasound-guided assessment of diaphragmatic efficiency.ResultsSixty mechanically ventilated patients were randomly divided into four equal groups (15 each): patients were ventilated using either assist control pressure-controlled mode (group A), synchronized intermittent mandatory ventilation pressure-controlled mode (group S), bi-level-positive airway pressure mode (group B) or pressure support ventilation mode (group P). The primary outcome was to assess the diaphragmatic excursion, while the secondary outcomes were to assess the diaphragmatic thickness fraction and the duration of the ICU stay. Patients in the P group had the highest diaphragmatic excursion indicating better diaphragmatic function.ConclusionsWhen compared to other pressure-targeted ventilation modes, the pressure support ventilation mode may have the least risk of diaphragmatic dysfunction as preserves diaphragmatic structure and strength.Trial registrationThe clinical trial was retrospectively registered at http://www.pactr.org PACTR202112653971335.

The Relationship Between Esophageal Pressure and Diaphragm Thickening Fraction in Spontaneously Breathing Sedated Children: A Feasibility Study.

Diaphragm ultrasound is a novel alternative to esophageal pressure measurements in the evaluation of diaphragm function and activity, but data about its reliability in a pediatric setting are lacking. We aimed to compare the esophageal pressure swing (∆Pes, gold standard) with the diaphragmatic thickening fraction (DTF) as a measure of inspiratory effort in sedated children. Additionally, we studied the effect of positive end-expiratory pressure (PEEP) on the end-expiratory thickness of the diaphragm (DTee). Prospective open-label non-randomized interventional physiological cohort study. Operating room in tertiary academic hospital. Children 28 days to 13 years old scheduled for elective surgery with general anesthesia, spontaneously breathing through a laryngeal mask airway, were eligible for inclusion. Exclusion criteria were disorders or previous surgery of the diaphragm, anticipated difficult airway or acute cardiopulmonary disease. All measurements were performed prior to surgery. Patients were subjected to different levels of respiratory load, PEEP and anesthetic depth in a total of seven respiratory conditions. The esophageal pressure and diaphragm thickening fraction were simultaneously recorded for five breaths at each respiratory condition. The relation between ∆Pes and DTF was studied in a mixed model. We analyzed 407 breaths in 13 patients. Both DTF (p = 0.03) and ∆Pes (p = 0.002) could detect respiratory activity, and ∆Pes and DTF were associated across respiratory conditions (p < 0.001; R2 = 31%). With increasing inspiratory load, ∆Pes increased significantly, while DTF did not (p = 0.08). Additionally, DTee did not differ significantly between 10, 5, and 0 cm H2O PEEP (p = 0.08). In spontaneously breathing sedated children and across different respiratory conditions, DTF could differentiate minimal or no inspiratory effort from substantial inspiratory effort and was associated with ∆Pes. Increased efforts resulted in higher ∆Pes but not larger DTF.