Diaphragm Movement Before and After Cholecystectomy: A Sonographic Study

Ultrasonographic Assessment of Diaphragmatic Inspiratory Amplitude and Its Association with Postoperative Pulmonary Complications in Upper Abdominal Surgery: A Prospective, Longitudinal, Observational Study

Background

Diaphragmatic dysfunction following upper abdominal surgery is less recognized due to a lack of diagnostic modality for bedside evaluation. We used point-of-care ultrasound to evaluate the diaphragmatic inspiratory amplitude (DIA) in upper abdominal surgery for cancer. Our primary hypothesis was DIA would be reduced in the immediate postoperative period in patients with postoperative pulmonary complications (PPCs). Our aim was to identify an optimal cutoff of DIA for the diagnosis of PPCs.

Methods

We conducted a prospective, observational study in patients aged 18-75 years undergoing elective, upper abdominal oncological surgeries under combined general and epidural anesthesia. Ultrasound evaluation of the diaphragm was done by measuring the DIA in the right and left hemidiaphragms during quiet and deep breathing on the day before surgery and postoperative days (PODs) 1, 2, and 3. Patients were followed up for PPCs until POD 7. The linear mixed-effects model examined the association between DIA and PPCs and other perioperative factors. Receiver-operating characteristics analysis was done to determine the optimal cutoff of DIA in diagnosing PPCs.

Results

DIA measured in the 162 patients showed a significant decrease in their absolute values postoperatively from its preoperative baseline measurement. This decrease in DIA was significantly associated with PPC [right hemidiaphragm, β = -0.17, 95% confidence interval (CI) -0.31 to -0.02, p = 0.001 during quiet breathing; left hemidiaphragm, β = -0.24, 95% CI = -0.44 to -0.04, p = 0.018 and β = -0.40, 95% CI = -0.71 to -0.09, p = 0.012 during quiet and deep breathing, respectively]. A cutoff value of DIA of left hemidiaphragm at 1.3 cm during quiet breathing and 1.6 cm during deep breathing had a sensitivity of 77 and 75%, respectively, in their ability to diagnose PPCs [left hemidiaphragm quiet breathing, area under the curve (AUC): 0.653, 95% CI 0.539-0.768, p = 0.015; left hemidiaphragm deep breathing, AUC: 0.675, 95% CI 0.577-0.773, p = 0.007].

Conclusion

Following upper abdominal surgery, the DIA is decreased and associated with PPCs. DIA of left hemidiaphragm less than 1.3 cm during quiet breathing and 1.6 cm during deep breathing has a sensitivity of 77 and 75%, respectively, in diagnosing PPCs following upper abdominal surgery.

How to cite this article

Vanamail PV, Balakrishnan K, Prahlad S, Chockalingam P, Dash R, Soundararajan DK. Ultrasonographic Assessment of Diaphragmatic Inspiratory Amplitude and Its Association with Postoperative Pulmonary Complications in Upper Abdominal Surgery: A Prospective, Longitudinal, Observational Study. Indian J Crit Care Med 2021;25(9):1031-1039.

Is sarcopenia a risk factor for reduced diaphragm function following hepatic resection? A study protocol for a prospective observational study

INTRODUCTION

Sarcopenia is associated with reduced pulmonary function in healthy adults, as well as with increased risk of pneumonia following abdominal surgery. Consequentially, postoperative pneumonia prolongs hospital admission, and increases in-hospital mortality following a range of surgical interventions. Little is known about the function of the diaphragm in the context of sarcopenia and wasting disorders or how its function is influenced by abdominal surgery. Liver surgery induces reactive pleural effusion in most patients, compromising postoperative pulmonary function. We hypothesise that both major hepatic resection and sarcopenia have a measurable impact on diaphragm function. Furthermore, we hypothesise that sarcopenia is associated with reduced preoperative diaphragm function, and that patients with reduced preoperative diaphragm function show a greater decline and reduced recovery of diaphragm function following major hepatic resection. The primary goal of this study is to evaluate whether sarcopenic patients have a reduced diaphragm function prior to major liver resection compared with non-sarcopenic patients, and to evaluate whether sarcopenic patients show a greater reduction in respiratory muscle function following major liver resection when compared with non-sarcopenic patients.

METHODS AND ANALYSIS

Transcostal B-mode, M-mode ultrasound and speckle tracking imaging will be used to assess diaphragm function perioperatively in 33 sarcopenic and 33 non-sarcopenic patients undergoing right-sided hemihepatectomy starting 1 day prior to surgery and up to 30 days after surgery. In addition, rectus abdominis and quadriceps femoris muscles thickness will be measured using ultrasound to measure sarcopenia, and pulmonary function will be measured using a hand-held bedside spirometer. Muscle mass will be determined preoperatively using CT-muscle volumetry of abdominal muscle and adipose tissue at the third lumbar vertebra level (L3). Muscle function will be assessed using handgrip strength and physical condition will be measured with a short physical performance battery . A rectus abdominis muscle biopsy will be taken intraoperatively to measure proteolytic and mitochondrial activity as well as inflammation and redox status. Systemic inflammation and sarcopenia biomarkers will be assessed in serum acquired perioperatively.

ETHICS AND DISSEMINATION

This trial is open for recruitment. The protocol was approved by the official Independent Medical Ethical Committee at Uniklinik (Rheinish Westphälische Technische Hochschule (RWTH) Aachen (reference EK309-18) in July 2019. Results will be published via international peer-reviewed journals and the findings of the study will be communicated using a comprehensive dissemination strategy aimed at healthcare professionals and patients.

TRIAL REGISTRATION NUMBER

ClinicalTrials. gov (EK309-18); Pre-results.

Diaphragmatic Function Assessed by Bed Side Ultrasonography in Patients with Sepsis or Septic Shock Admitted to Intensive Care Unit

BACKGROUND: Sepsis and septic shock are major problems faced the healthcare systems all over the world every year. The ultrasound (US) is a simple, non-invasive, easily accessible technique, and showed great accuracy in diaphragm assessment. AIM: We evaluated the diaphragmatic function assessed by US in patients with sepsis and septic shock and correlated these assessments with different parameters. MATERIALS AND METHODS: A prospective observational study carried out on 30 patients admitted to the intensive care unit (ICU) diagnosed with sepsis and/or septic shock. Both diaphragmatic excursion (DE) and thickness fraction (diaphragm thickening fraction [TDI] %) were assessed by US on admission and every 48 h along the patients’ ICU stay. RESULTS: In the current study, there was a statistically significant reverse relationship between mortality and the different diaphragmatic function parameters (DE on admission, average DE, on admission TDI%, average TDI%). On the other hand, the DE (on admission and average) showed a statistically significant reverse relation with the need and duration of mechanical ventilation (MV) while the TDI% showed a statistically significant reverse relation only with the duration of MV. Besides, there was a statistically significant direct relationship between successful weaning from MV and all the measured parameters. CONCLUSION: We proposed that the diaphragmatic function parameters (DE on admission, average DE, on admission TDI% and average TDI%) assessed by US of septic ICU patients could be used as a predictor of the need, duration, and successful weaning from MV and also as a predictor of mortality.

Ultrasonographic assessment of diaphragmatic contraction and relaxation properties: correlations of diaphragmatic displacement with oesophageal and transdiaphragmatic pressure

Transdiaphragmatic (Pdi) and oesophageal pressures (Pes) are useful in understanding the pathophysiology of the respiratory system. They provide insight into respiratory drive, intrinsic positive end-expiratory pressure, diaphragmatic fatigue and weaning failure.

Sugammadex Versus Neostigmine for Reversal of Rocuronium Neuromuscular Block in Patients Having Catheter-Based Neurointerventional Procedures: A Randomized Trial

BACKGROUND

Catheter-based endovascular neurointerventions require deep neuromuscular blocks during the procedure and rapid subsequent recovery of strength to facilitate neurological evaluation. We tested the primary hypothesis that sugammadex reverses deep neuromuscular blocks faster than neostigmine reverses moderate neuromuscular blocks.

METHODS

Patients having catheter-based cerebral neurointerventional procedures were randomized to: (1) deep rocuronium neuromuscular block with posttetanic count 1 to 2 and 4-mg/kg sugammadex as the reversal agent or (2) moderate rocuronium neuromuscular block with train-of-four (TOF) count 1 during the procedure and neuromuscular reversal with 0.07-mg/kg neostigmine to a maximum of 5 mg. Recovery of diaphragmatic function was assessed by ultrasound at baseline before the procedure and 90 minutes thereafter. The primary outcome-time to reach a TOF ratio ≥0.9 after administration of the designated reversal agent-was analyzed with a log-rank test. Secondary outcomes included time to successful tracheal extubation and the difference between postoperative and preoperative diaphragmatic contraction speed and distance.

RESULTS

Thirty-five patients were randomized to sugammadex and 33 to neostigmine. Baseline characteristics and surgical factors were well balanced. The median time to reach TOF ratio ≥0.9 was 3 minutes (95% confidence interval [CI], 2-3 minutes) in patients given sugammadex versus 8 minutes (95% CI, 6-10 minutes) in patients given neostigmine. Sugammadex was significantly faster by a median of 5 minutes (95% CI, 3-6 minutes; P < .001). However, times to tracheal extubation and diaphragmatic function at 90 minutes did not differ significantly.

CONCLUSIONS

Sugammadex reversed deep rocuronium neuromuscular blocks considerably faster than neostigmine reversed moderate neuromuscular blocks. However, times to extubation did not differ significantly, apparently because extubation was largely determined by the time required for awaking from general anesthesia and because clinicians were willing to extubate before full neuromuscular recovery. Sugammadex may nonetheless be preferable to procedures that require a deep neuromuscular block and rapid recovery.

Detecting Ventilator-Induced Diaphragmatic Dysfunction Using Point-of-Care Ultrasound in Children With Long-term Mechanical Ventilation

Long-term mechanical ventilation (MV) is defined as the use of MV for more than 6 hours per day for at least 3 weeks. Children requiring long-term MV include those with neuromuscular disease, central dysregulation, or lung dysfunction. Such children with medical complexity may be at risk for ventilator-induced diaphragmatic dysfunction. Ventilator-induced diaphragmatic dysfunction has been described in adult patients requiring acute MV with ultrasound (US). At this time, diaphragmatic US has not been evaluated in the pediatric post-acute care setting or incorporated into weaning strategies. We present 24 cases of children requiring long-term MV who underwent diaphragmatic US examinations to evaluate for ventilator-induced diaphragmatic dysfunction.

Ultrasound and non-ultrasound imaging techniques in the assessment of diaphragmatic dysfunction

Diaphragm muscle dysfunction is increasingly recognized as an important element of several diseases including neuromuscular disease, chronic obstructive pulmonary disease and diaphragm dysfunction in critically ill patients. Functional evaluation of the diaphragm is challenging. Use of volitional maneuvers to test the diaphragm can be limited by patient effort. Non-volitional tests such as those using neuromuscular stimulation are technically complex, since the muscle itself is relatively inaccessible. As such, there is a growing interest in using imaging techniques to characterize diaphragm muscle dysfunction. Selecting the appropriate imaging technique for a given clinical scenario is a critical step in the evaluation of patients suspected of having diaphragm dysfunction. In this review, we aim to present a detailed analysis of evidence for the use of ultrasound and non-ultrasound imaging techniques in the assessment of diaphragm dysfunction. We highlight the utility of the qualitative information gathered by ultrasound imaging as a means to assess integrity, excursion, thickness, and thickening of the diaphragm. In contrast, quantitative ultrasound analysis of the diaphragm is marred by inherent limitations of this technique, and we provide a detailed examination of these limitations. We evaluate non-ultrasound imaging modalities that apply static techniques (chest radiograph, computerized tomography and magnetic resonance imaging), used to assess muscle position, shape and dimension. We also evaluate non-ultrasound imaging modalities that apply dynamic imaging (fluoroscopy and dynamic magnetic resonance imaging) to assess diaphragm motion. Finally, we critically review the application of each of these techniques in the clinical setting when diaphragm dysfunction is suspected.

Diaphragmatic excursion: Quantitative measure to assess adequacy of expiratory phase CT chest images

OBJECTIVE

To evaluate diaphragmatic excursion as a quantitative metric for change in lung volume between inspiratory and expiratory chest computed tomography (CT) images.

METHODS

A 12-month retrospective review identified 226 chest CT exams with inspiratory and expiratory phase imaging, 63 in individuals referred with diagnosis of asthma by ICD9/10 code. Exams acquired in the supine position at 1.25 mm slice thickness in each phase were included (n = 30, mean age = 62, M = 15, F = 15). Diaphragmatic excursion was calculated as the difference between axial slices through the lungs on inspiration and expiration, using the lung apex as the cranial bound, and the hemidiaphragm caudally. Inspiratory and expiratory lung and tracheal volumes were calculated through volumetric segmentation. Tracheal morphology was assessed at 1 cm above the level of the aortic arch, and 1 cm above the carina.

RESULTS

Inspiratory and expiratory lung volumes were higher in men (mean I = 5 + 1.6 L, E = 3.1 + 1.2 L) than women (mean I = 3.6 + 0.8 L, E = 2.4 + 0.7 L), p = .005 and p = .047, respectively. Average inspiratory and expiratory tracheal volumes were higher in men (I = 61 + 17 mL, E = 43 + 14) than women (I = 44 + 14, E = 30 + 8), p = .006 and p = .005. Average change in lung and tracheal volume between inspiratory and expiratory scans did not significantly differ between men and women. Average diaphragmatic excursion was 2.5 cm between inspiratory and expiratory scans (2.7 cm in men, 2.3 cm in women; p = .5). There was a strong positive correlation between diaphragmatic excursion and change in lung (r = .84) and tracheal volume (r = .79). A moderate correlation was also found between change in tracheal volume and change in lung volume (r = 0.67). Change in tracheal morphology between inspiratory and expiratory imaging was associated with change in tracheal volume at both 1 cm above the aortic arch (p = .04) and 1 cm above the carina (p = .008); there was no association with diaphragmatic excursion or lung volume.

CONCLUSIONS

Diaphragmatic excursion is a quantitative measure of expiratory effort as validated by both lung and tracheal volumes in asthma patients, and may be more accurate than qualitative assessment based on tracheal morphology.

Ultrasound diaphragmatic manual and semi-automated motion measurements: Application in simulated and in vivo data of critically ill subjects

BACKGROUND AND OBJECTIVE

Ultrasound diaphragmatic muscle motion characteristics may provide useful information about normal or abnormal diaphragmatic function and indicate diaphragmatic weakness, or paralysis. In the present work we propose and evaluate an integrated semi-automated analysis system for the quantitative analysis of ultrasonic motion from ultrasound diaphragmatic videos.

METHODS

The proposed system was evaluated in simulated videos and in 13 patients, four of whom patients were mechanically ventilated. The major steps of the methodology were as follows: video normalization, despeckle filtering, generation of an M-Mode image, snakes segmentation, and motion measurements.

RESULTS

The following manual (-/) vs semi-automated (/-), (median±IQR) measurements, which are routinely carried out by the experts, for assessing the severity of the disease, were computed. For the simulated videos the diaphragmatic excursion was 1.80±0.00 cm / 1.76±0.03 cm. For all the real ultrasound videos investigated in this study the following measurements were computed: (i) diaphragmatic excursion: 0.84±0.15 cm / 0.83±0.14 cm, (ii) inspiration time (T_insp): 0.71±0.18 sec / 0.70±0.15 sec, (iii) total breathing time for one cycle (T_tot): 1.71±0.37 sec / 1.67±0.37 sec, (iv) diaphragmatic curve slope: 1.29±0.36 cm/sec / 1.27±0.36 cm/sec, and (v) relaxation rate (RR): 0.82±0.17 cm/sec / 0.82±0.18 cm/sec.

CONCLUSIONS

Manual and semi-automated measurements were very close with non-statistical significant differences and strong correlations between them. It is anticipated that the proposed system might be useful in the clinical practice in the assessment and follow up of patients with diaphragmatic weakness or paralysis and aid in the separation of normal and abnormal diaphragmatic motion. Further validation and additional experimentation in a larger sample of videos and different patient groups is required.

Diaphragmatic excursion measurement in emergency department patients with acute dyspnea to predict mechanical ventilation use

INTRODUCTION

Ultrasound is a feasible and reproducible method for measuring right diaphragmatic excursion (RDE) in ED patients with acute dyspnea (AD). In AD patients, the correlation between the RDE value and the need for mechanical ventilation (MV) is not known.

MATERIALS

This was a bicentric, observational prospective study. The RDE measurement was done at admission. The need for MV was defined by the use of MV within 4 h of AD management. An optimal threshold for RDE was determined as the value that minimized the incorrect predictions of the use of MV in the first 4 h as the highest Youden index.

RESULTS

We analyzed 102 patients (79 [70; 86] years), 38 (37%) of whom had been ventilated. The RDE value was 1.7 cm [1.4; 2.0] and 2.2 cm [1.8; 2.6] in the ventilated and non-ventilated groups, respectively (p = 0.06). The AUC was 0.68 95% CI [0.57; 0.80]. With a threshold of 2 cm, the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were 76% [60%; 89%], 59% [46%; 71%], 81% [67%; 91%], and 53% [39%; 66%], respectively. In the non-COPD patients, the RDE values were 1.5 cm [1.2; 1.9] and 2.2 cm [1.8; 2.6] (p < 0.01) in the ventilated and not-ventilated groups, respectively. The AUC was 0.77 95% CI [0.64; 0.90]. With a threshold of 2.18 cm, the sensitivity, specificity, NPV, and PPV were 91% [71%; 99%], 51% [36%; 66%], 92% [75%; 99%], and 54% [38%; 69%], respectively.

CONCLUSION

The RDE values at ED admission were unable to define a prognostic threshold value associated with subsequent MV need in the AD patients. In non-COPD patients, the NPV was 92%.

Tracheal, Lung, and Diaphragmatic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care

Today, proficiency in cardiopulmonary ultrasound is considered essential for anesthesiologists and critical care physicians. Conventional 2-dimensional images, however, do not permit optimal characterization of specific conditions (eg, diaphragmatic paralysis, major atelectasis, and pneumothorax) that may have relevant clinical implications in critical care and perioperative settings. By contrast, M-mode (motion-based) ultrasonographic imaging modality offers the highest temporal resolution in ultrasonography; this modality, therefore, can provide important information in ultrasound-driven approaches performed by anesthesiologists and intensivists for diagnosis, monitoring, and procedural guidance. Despite its practicability, M-mode has been progressively abandoned in echocardiography and is often underused in lung and diaphragmatic ultrasound. This review describes contemporary applications of M-mode ultrasonography in the practice of critical care and perioperative medicine. Information presented for each clinical application includes image acquisition and interpretation, evidence-based clinical implications in critically ill and surgical patients, and main limitations. The article focuses on tracheal, lung, and diaphragmatic ultrasound. It reviews tracheal ultrasound for procedural guidance during endotracheal intubation, confirmation of correct tube placement, and detection of esophageal intubation; lung ultrasound for the confirmation of endotracheal and endobronchial (selective) intubation and for the diagnosis of pneumothorax, alveolar-interstitial syndrome (cardiogenic v noncardiogenic pulmonary edema), pulmonary consolidation (pneumonia v major atelectasis) and pleural effusion; and diaphragmatic ultrasound for the diagnosis of diaphragmatic dysfunction and prediction of extubation success.

Changes of diaphragmatic excursion and lung compliance during major laparoscopic pelvic surgery: A prospective observational study

Major laparoscopic pelvic surgery requires steep Trendelenburg position with pneumoperitoneum for a long time. We investigated the effect of Trendelenburg position with pneumoperitoneum on diaphragmatic excursion and lung compliance during major laparoscopic pelvic surgery using M-mode sonography. Twenty patients undergoing elective pelviscopic radical hysterectomy were included in this study. Diaphragmatic excursion was measured at the following time points; after sedation, after intubation, 90 minutes after Trendelenburg position with pneumoperitoneum, and after operation with recovery of muscle relaxation. And lung compliance was measured using anesthetic machine under general anesthesia; after the intubation, 90 minutes after Trendelenburg position with pneumoperitoneum and after operation with recovery of muscle relaxation. In order to detect postoperative pulmonary complication, postoperative chest radiography was checked. Static lung compliance, dynamic lung compliance and diaphragmatic excursion were decreased during operation (P < 0.001, respectively). At the end of the operation with recovery of muscle relaxation, reduced diaphragmatic movement was not recovered as its excursion after sedation (P < 0.001). In conclusion, lung compliance was decreased following transiently decreased diaphragmatic excursion during major laparoscopic pelvic surgery.

Ultrasound Identification of Diaphragm by Novices Using ABCDE Technique

BACKGROUND AND OBJECTIVES

In this study, we examined the consistency, rapidity, and reproducibility of the ABCDE technique for diaphragm identification. Operators using this method place the probe at the Anterior axillary line, watch for Breathing (lung sliding), and then move the probe Caudally to identify the Diaphragm for Examination.

METHODS

A convenience sample of 100 patients was recruited from the preadmission clinic. Two novice operators each scanned the diaphragm using a linear ultrasound transducer in B-mode. Both operators completed the examination on all participants using the ABCDE technique, their times were averaged, and clinical success was defined as identification of the diaphragm in less than 2 minutes.

RESULTS

An average of 33.7 seconds was taken to scan and identify the right hemidiaphragm (RD) (median, 25 seconds; 95% confidence interval, 28.8-38.5 seconds) with a 98% clinical success ratio, and an average of 46.9 seconds was taken to identify the left hemidiaphragm (LD) (median, 39.5 seconds; 95% confidence interval, 40.2-53.6 seconds) with a 97% clinical success ratio. In patients with a body mass index (BMI) of less than 30 kg/m, a 100% success ratio was seen when scanning the RD and 97% when scanning the LD. For those with a BMI of 30 kg/m or greater, a 94% success rate was seen when scanning the RD and 97% when scanning the LD. No clinically significant differences were found between the times required for scanning either side of the diaphragm, regardless of the BMI.

CONCLUSIONS

The ABCDE technique demonstrates a fast, reliable, and simple method in which ultrasound can be used to visualize the diaphragm.

Validity and reliability of assessing diaphragmatic mobility by area on X-rays of healthy subjects

OBJECTIVE

To investigate the concurrent validity, as well as the intra- and inter-rater reliability, of assessing diaphragmatic mobility by area (DMarea) on chest X-rays of healthy adults.

METHODS

We evaluated anthropometric parameters, pulmonary function, and diaphragmatic mobility in 43 participants. Two observers (rater A and rater B) determined diaphragmatic mobility at two time points. We used Pearson's correlation coefficient to evaluate the correlation between DMarea and the assessment of diaphragmatic mobility by distance (DMdist). To evaluate intra- and inter-rater reliability, we used the intraclass correlation coefficient (ICC [2,1]), 95% CI, and Bland-Altman analysis.

RESULTS

A significant correlation was found between the DMarea and DMdist methods (r = 0.743; p < 0.0001). For DMarea, the intra-rater reliability was found to be quite high for the right hemidiaphragm (RHD)-ICC (2,1) = 0.92 (95% CI: 0.86-0.95) for rater A and ICC (2,1) = 0.90 (95% CI: 0.84-0.94) for rater B-and the left hemidiaphragm (LHD)-ICC (2,1) = 0.96 (95% CI: 0.93-0.97) for rater A and ICC (2,1) = 0.91 (95% CI: 0.81-0.95) for rater B-(p < 0.0001 for all). Also for DMarea, the inter-rater reliability was found to be quite high for the first and second evaluations of the RHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.95 (95% CI: 0.86-0.97), respectively-and the LHD-ICC (2,1) = 0.99 (95% CI: 0.98-0.99) and ICC (2,1) = 0.94 (95% CI: 0.87-0.97)-(p < 0.0001 for both). The Bland-Altman analysis showed good agreement between the mobility of the RHD and that of the LHD.

CONCLUSIONS

The DMarea method proved to be a valid, reliable measure of diaphragmatic mobility.

Towards estimation of respiratory muscle effort with respiratory inductance plethysmography signals and complementary ensemble empirical mode decomposition

Respiratory inductance plethysmography (RIP) sensor is an inexpensive, non-invasive, easy-to-use transducer for collecting respiratory movement data. Studies have reported that the RIP signal's amplitude and frequency can be used to discriminate respiratory diseases. However, with the conventional approach of RIP data analysis, respiratory muscle effort cannot be estimated. In this paper, the estimation of the respiratory muscle effort through RIP signal was proposed. A complementary ensemble empirical mode decomposition method was used, to extract hidden signals from the RIP signals based on the frequency bands of the activities of different respiratory muscles. To validate the proposed method, an experiment to collect subjects' RIP signal under thoracic breathing (TB) and abdominal breathing (AB) was conducted. The experimental results for both the TB and AB indicate that the proposed method can be used to loosely estimate the activities of thoracic muscles, abdominal muscles, and diaphragm. Graphical abstract ᅟ.

Comparative study of respiratory muscle strength in women undergoing conventional and single-port laparoscopic cholecystectomy

PURPOSE

To evaluate respiratory muscle strength (PImax and PEmax) before and 24 and 48 h after conventional and single-port laparoscopic cholecystectomy.

METHODS

Forty women with symptomatic cholelithiasis (18 to 70 years) participated in the study. The patients were divided into two groups: 21 patients undergoing conventional laparoscopic cholecystectomy and 19 patients undergoing single-port laparoscopic cholecystectomy. Differences were considered to be significant when p<0.05.

RESULTS

The results showed a greater decline in PImax after 24 h in the group submitted to conventional laparoscopic cholecystectomy, with a significant difference between groups (p=0.0308).

CONCLUSION

Recovery of the parameters studied was more satisfactory and respiratory muscle strength was less compromised in the group submitted to single-port laparoscopic cholecystectomy.

Functional assessment of the diaphragm by speckle tracking ultrasound during inspiratory loading

Assessment of diaphragmatic effort is challenging, especially in critically ill patients in the phase of weaning. Fractional thickening during inspiration assessed by ultrasound has been used to estimate diaphragm effort. It is unknown whether more sophisticated ultrasound techniques such as speckle tracking are superior in the quantification of inspiratory effort. This study evaluates the validity of speckle tracking ultrasound to quantify diaphragm contractility. Thirteen healthy volunteers underwent a randomized stepwise threshold loading protocol of 0-50% of the maximal inspiratory pressure. Electric activity of the diaphragm and transdiaphragmatic pressures were recorded. Speckle tracking ultrasound was used to assess strain and strain rate as measures of diaphragm tissue deformation and deformation velocity, respectively. Fractional thickening was assessed by measurement of diaphragm thickness at end-inspiration and end-expiration. Strain and strain rate increased with progressive loading of the diaphragm. Both strain and strain rate were highly correlated to transdiaphragmatic pressure (strain r² = 0.72; strain rate r² = 0.80) and diaphragm electric activity (strain r² = 0.60; strain rate r² = 0.66). We conclude that speckle tracking ultrasound is superior to conventional ultrasound techniques to estimate diaphragm contractility under inspiratory threshold loading.NEW & NOTEWORTHY Transdiaphragmatic pressure using esophageal and gastric balloons is the gold standard to assess diaphragm effort. However, this technique is invasive and requires expertise, and the interpretation may be complex. We report that speckle tracking ultrasound can be used to detect stepwise increases in diaphragmatic effort. Strain and strain rate were highly correlated with transdiaphragmatic pressure, and therefore, diaphragm electric activity and speckle tracking might serve as reliable tools to quantify diaphragm effort in the future.

[Exploring the diaphragm: Ultrasound is essential]

The diaphragm is the muscle most implicated in breathing. Its morphological exploration usually depends on pulmonary radiography, fluoroscopy, CT-scanning and MRI. Its function is evaluated by the classical respiratory functional tests, the measurement of maximum inspiratory and expiratory pressures, the transdiaphragmatic pressure and even an electromyogram. Ultrasound is a technique still insufficiently used in respiratory medicine. It offers, however, many advantages: it is easy to implement, there is no irradiation, it is usable at the bedside, particularly when the patient is immobile or in intensive care. The results of the examination are immediately available. It allows morphological and dynamic study of each hemidiaphragm as well as providing invaluable information on the thoracic and subdiaphragmatic environment. Its field of exploration is extremely wide: raised hemidiaphragm, dyspnea following a stroke or a surgical procedure (thoracic or abdominal), road accident trauma, diagnosis and follow-up of a paresis or paralysis, evaluation of diaphragmatic mobility during the course of COPD (Chronic Obstructive Pulmonary Disease) and many other pathologies. Ultrasound is insufficiently used in pleural disease and even less so in the evaluation of the morphology and function of the diaphragm.

Validity and reliability of fluoroscopy for digital radiography: a new way to evaluate diaphragmatic mobility

Background

Fluoroscopy is considered the most accurate method to evaluate the diaphragm, yet most existing methods for measuring diaphragmatic mobility using fluoroscopy are complex. To assess the validity and reliability of a new evaluation method of diaphragmatic motion using fluoroscopy by digital radiography of healthy adults.

Methods

Twenty-six adults were evaluated, according to the parameters: anthropometry and pulmonary function test. The evaluation of diaphragm mobility by means of fluoroscopy by digital radiography method was randomly conducted by two raters (A and B). The Pearson correlation coefficient and the intraclass correlation coefficient (ICC) were used to assess the concurrent validity. The inter-rater and intra-rater reliability of the measurement of diaphragmatic motion was determined using ICC and a confidence interval of 95%.

Results

There was a relationship in the assessment of the concurrent validity. There was good inter-rater reliability for right hemidiaphragm mobility and moderate reliability for left hemidiaphragm in the first assessment. In the second assessment, there was good reliability for the mobility of both hemidiaphragms. There was good intra-rater reliability in the mobility of both hemidiaphragms for raters A and B.

Conclusion

The evaluation of diaphragmatic motion using fluoroscopy by digital radiography proved to be a valid and reliable method of healthy adults.

Use of Angle-Independent M-Mode Sonography for Assessment of Diaphragm Displacement

OBJECTIVES

Sonographic assessment of diaphragm displacement has conventionally been conducted with M-mode sonography via an anterior subcostal approach. This method is subject to measurement errors when diaphragm displacement is not in line with the M-mode plane. We aimed to compare measurements obtained by offline angle-independent (anatomic) M-mode sonography with conventional M-mode sonography.

METHODS

Fifty healthy adults were imaged with conventional and angle-independent M-mode sonography of the bilateral hemidiaphragms at 60% maximal inspiratory capacity using an inspiratory spirometer.

RESULTS

Left hemidiaphragm displacement was successfully imaged by conventional M-mode sonography in only 70% (n = 35), as lung expansion obscured imaging, whereas 92% (n = 46) were assessable by angle-independent M-mode sonography. All right hemidiaphragm displacement could be assessed. Conventional M-mode results were higher than angle-independent M-mode results on the right (mean ± SD, 4.9 ± 1.4 versus 4.6 ± 1.2 cm, respectively; P= .003) and left (5.4 ± 1.3 versus 4.6 ± 1.0 cm; P < .001). Displacement values were different for right versus left hemidiaphragms on conventional M-mode sonography (mean difference, 0.6 ± 0.2 cm; P = .005), with only mild agreement (R² = 0.35; P < .001). There was no laterality seen in the diaphragm displacement on angle-independent M-mode sonography (mean difference, 0.1 ± 0.1 cm; P = .47), with good agreement (R² = 0.76; P < .001).

CONCLUSIONS

Angle-independent M-mode sonography leads to better visualization and assessment of the left hemidiaphragm. It records lower displacement than conventional M-mode sonography in the bilateral diaphragms, likely because of fewer orientation and translation errors. Future study is indicated to assess the clinical utility of angle-independent M-mode sonography in a population with diaphragm dysfunction.

[Diaphragm dysfunction : Facts for clinicians]

Diaphragm function is crucial for patient outcome in the ICU setting and during the treatment period. The occurrence of an insufficiency of the respiratory pump, which is predominantly formed by the diaphragm, may result in intubation after failure of noninvasive ventilation. Especially patients suffering from chronic obstructive pulmonary disease are in danger of hypercapnic respiratory failure. Changes in biomechanical properties and fiber texture of the diaphragm are further cofactors directly leading to a need for intubation and mechanical ventilation. After intubation and the following inactivity the diaphragm is subject to profound pathophysiologic changes resulting in atrophy and dysfunction. Besides this inactivity-triggered mechanism (termed as ventilator-induced diaphragmatic dysfunction) multiple factors, comorbidities, pharmaceutical agents and additional hits during the ICU treatment, especially the occurrence of sepsis, influence diaphragm homeostasis and can lead to weaning failure. During the weaning process monitoring of diaphragm function can be done with invasive methods - ultrasound is increasingly established to monitor diaphragm contraction, but further and better powered studies are in need to prove its value as a diagnostic tool.

Shrinking lung syndrome in systemic lupus erythematosus: A case series and review of the literature

Shrinking lung syndrome (SLS) is a rare and less known complication mainly associated with systemic lupus erythematosus (SLE). In this study, we analyze the clinical features, investigation findings, approaches to management, and outcome in a case series of 9 adult patients with SLE and SLS diagnosed during a 35-year period in 3 referral tertiary care hospitals in Spain. Additionally, we reviewed 80 additional cases previously reported (PubMed 1965-2015). These 80 cases, together with our 9 patients, form the basis of the present analysis.The overall SLS prevalence in our SLE population was 1.1% (9/829). SLS may complicate SLE at any time over its course, and it usually occurs in patients without previous or concomitant major organ involvement. More than half of the patients had inactive lupus according to SELENA-systemic lupus erythematosus disease activity index (SLEDAI) scores. Typically, it presents with progressive exertional dyspnea of variable severity, accompanied by pleuritic chest pain in 76% of the cases.An important diagnostic delay is common. The diagnostic tools that showed better yield for SLS detection are the imaging techniques (chest x-ray and high-resolution computed tomography) along with pulmonary and diaphragmatic function tests. Evaluation of diaphragm dome motion by M-mode ultrasonography and phrenic nerve conduction studies are less useful.There are no standardized guidelines for the treatment of SLS in SLE. The majority of patients were treated with medium or high doses of glucocorticoids. Several immunosuppressive agents have been used in conjunction with steroids either if the patient fails to improve or since the beginning of the treatment. Theophylline and beta-agonists, alone or in combination with glucocorticoids, have been suggested with the intent to increase diaphragmatic strength.The overall long-term prognosis was good. The great majority of patients had significant clinical improvement and stabilization, or mild to moderate improvement on pulmonary function tests. The mortality rate was very low.

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV₁), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery.

Interpreting diaphragmatic movement with bedside imaging, review article

The diaphragm is the most important muscle of respiration. At equilibrium, the load imposed on the diaphragmatic muscles from transdiaphragmatic pressure balances the force generated by diaphragmatic muscles. However, procedural and nonprocedural thoracic and abdominal conditions may disrupt this equilibrium and impair diaphragmatic function. Diaphragmatic dysfunction is associated with respiratory insufficiency and poor outcome. Therefore, rapid diagnosis and early intervention may be useful. Ultrasound imaging provides quick and accurate bedside assessment of the diaphragm. Various imaging techniques have been suggested, using 2-dimensional and M-mode technology. Diaphragm viewing depends on the degree of robe movement, determined by the angle of incidence of the ultrasound beam and by the direction of probe movement. In this review, we will discuss the function of the diaphragm focusing on clinically important anatomical and physiological properties of the diaphragm. We will review the literature regarding various sonographic techniques for diaphragm assessment. We will also explore the evidence for the role of the tidal displacement of subdiaphragmatic organs as a surrogate for diaphragm movement.

Measurement of ultrasonic diaphragmatic motion

The motion characteristics of the diaphragmatic muscle may provide useful information about normal and abnormal diaphragmatic function and indicate diaphragmatic weakness. The objective of this paper was to introduce a simple system for the quantitative analysis of ultrasonic diaphragmatic motion. The measurements routinely carried out by the experts were computed and these include: (i) excursion, (ii) inspiration time (Tinsp) and (iii) cycle duration (Ttot). The system was evaluated on four simulated videos and one real video. Manual and automated measurements were very close. Further work in a larger number of videos is needed for validating the proposed method.

Evaluation of lung volumes, vital capacity and respiratory muscle strength after cervical, thoracic and lumbar spinal surgery

CONTEXT AND OBJECTIVE

Studies have shown that physiopathological changes to the respiratory system can occur following thoracic and abdominal surgery. Laminectomy is considered to be a peripheral surgical procedure, but it is possible that thoracic spinal surgery exerts a greater influence on lung function. The aim of this study was to evaluate the pulmonary volumes and maximum respiratory pressures of patients undergoing cervical, thoracic or lumbar spinal surgery.

DESIGN AND SETTING

Prospective study in a tertiary-level university hospital.

METHODS

Sixty-three patients undergoing laminectomy due to diagnoses of tumors or herniated discs were evaluated. Vital capacity, tidal volume, minute ventilation and maximum respiratory pressures were evaluated preoperatively and on the first and second postoperative days. Possible associations between the respiratory variables and the duration of the operation, surgical diagnosis and smoking status were investigated.

RESULTS

Vital capacity and maximum inspiratory pressure presented reductions on the first postoperative day (20.9% and 91.6%, respectively) for thoracic surgery (P = 0.01), and maximum expiratory pressure showed reductions on the first postoperative day in cervical surgery patients (15.3%; P = 0.004). The incidence of pulmonary complications was 3.6%.

CONCLUSIONS

There were reductions in vital capacity and maximum respiratory pressures during the postoperative period in patients undergoing laminectomy. Surgery in the thoracic region was associated with greater reductions in vital capacity and maximum inspiratory pressure, compared with cervical and lumbar surgery. Thus, surgical manipulation of the thoracic region appears to have more influence on pulmonary function and respiratory muscle action.

Ultrasound analysis of diaphragm kinetics and the diagnosis of airway obstruction: the role of the M-mode index of obstruction

Diaphragm motion in forced expiration can be analyzed using M-mode ultrasound in an anterior subcostal approach. Maximum expiratory diaphragmatic excursion (EDEMax) and forced expiratory diaphragmatic excursion in the first second (FEDE1) are considered the physiopathological analogues of vital capacity (VC) and forced expiratory volume in the first second (FEV1). As the FEV1/VC % ratio is used as a marker of obstruction, our aim was to determine if the ratio FEDE1/EDEMax (M-mode index of obstruction [MIO]) differs between healthy subjects and patients with airway obstruction. One hundred twenty-four outpatients were examined by diaphragm ultrasound after spirometry. The MIO, expressed as the mean ± standard deviation (range), was 87.08 ± 6.64 (72.84-100) in the healthy group (N = 61) and 67.09 ± 12.49 (33.33-91.30) in the group with obstructed airways (N = 63). The difference between the two groups was significant (p < 0.0001), and MIO was significantly correlated with FEV1/VC (p < 0.0001). A MIO <77 was identified as a possibile cutoff for suspecting an obstructive spirometric pattern with a 95.5% positive predictive value. The MIO can be interpreted as a speed index of diaphragmatic relaxation that seems to be slower in obstructed patients and could be used to screen for obstructed airway diseases.

Two-dimensional ultrasound imaging of the diaphragm: quantitative values in normal subjects

INTRODUCTION

Real time ultrasound imaging of the diaphragm is an under-used tool in the evaluation of patients with unexplained dyspnea or respiratory failure.

METHODS

We measured diaphragm thickness and the change in thickness that occurs with maximal inspiration in 150 normal subjects, with results stratified for age, gender, body mass index, and smoking history.

RESULTS

The lower limit of normal diaphragm thickness at end expiration or functional residual capacity is 0.15 cm, and an increase of at least 20% in diaphragm thickness from functional residual capacity to total lung capacity is normal. A side to side difference in thickness at end expiration of > 0.33 cm is abnormal. Diaphragm thickness and contractility are minimally affected by age, gender, body habitus, or smoking history.

CONCLUSIONS

This study confirms previous findings in much smaller groups of normal controls for quantitative ultrasound of the diaphragm and provides data that can be applied widely to the general population.

Shrinking lung syndrome as a manifestation of pleuritis: a new model based on pulmonary physiological studies

OBJECTIVE

The pathophysiology of shrinking lung syndrome (SLS) is poorly understood. We sought to define the structural basis for this condition through the study of pulmonary mechanics in affected patients.

METHODS

Since 2007, most patients evaluated for SLS at our institutions have undergone standardized respiratory testing including esophageal manometry. We analyzed these studies to define the physiological abnormalities driving respiratory restriction. Chest computed tomography data were post-processed to quantify lung volume and parenchymal density.

RESULTS

Six cases met criteria for SLS. All presented with dyspnea as well as pleurisy and/or transient pleural effusions. Chest imaging results were free of parenchymal disease and corrected diffusing capacities were normal. Total lung capacities were 39%-50% of predicted. Maximal inspiratory pressures were impaired at high lung volumes, but not low lung volumes, in 5 patients. Lung compliance was strikingly reduced in all patients, accompanied by increased parenchymal density.

CONCLUSION

Patients with SLS exhibited symptomatic and/or radiographic pleuritis associated with 2 characteristic physiological abnormalities: (1) impaired respiratory force at high but not low lung volumes; and (2) markedly decreased pulmonary compliance in the absence of identifiable interstitial lung disease. These findings suggest a model in which pleural inflammation chronically impairs deep inspiration, for example through neural reflexes, leading to parenchymal reorganization that impairs lung compliance, a known complication of persistently low lung volumes. Together these processes could account for the association of SLS with pleuritis as well as the gradual symptomatic and functional progression that is a hallmark of this syndrome.

Neuromuscular ultrasound for evaluation of the diaphragm

Neuromuscular clinicians are often asked to evaluate the diaphragm for diagnostic and prognostic purposes. Traditionally, this evaluation is accomplished through history, physical exam, fluoroscopic sniff test, nerve conduction studies, and electromyography (EMG). Nerve conduction studies and EMG in this setting are challenging, uncomfortable, and can cause serious complications, such as pneumothorax. Neuromuscular ultrasound has emerged as a non-invasive technique that can be used in the structural and functional assessment of the diaphragm. In this study we review different techniques for assessing the diaphragm using neuromuscular ultrasound and the application of these techniques to enhance diagnosis and prognosis by neuromuscular clinicians.

Evaluating systemic lupus erythematosus patients for lung involvement

Introduction: We set out to determine the frequency of respiratory symptoms, abnormal lung function, and shrinking lung syndrome (SLS) among patients with systemic lupus erythematosus (SLE) and to determine correlates of SLS. Methods: Consecutive adult patients who fulfilled the American College of Rheumatology classification criteria for SLE were enrolled. Demographics, clinical, and serologic characteristics were recorded; all patients underwent pulmonary function tests (PFT) and had either a chest X-ray or computed tomography scan. SLS was defined as dyspnea with restrictive lung physiology (defined as a forced vital capacity (FVC) <80% predicted in the absence of obstruction) who did not have any evidence of interstitial lung disease on chest imaging; controls were symptomatic patients with no restrictive physiology and the absence of interstitial changes on chest imaging. Results: Sixty-nine out of 110 (63%) patients had respiratory symptoms, 73 (66%) patients had abnormal lung function, and 11 (10%) patients met the definition for SLS. In a multivariate model controlling for disease duration, a history of pleuritis, modified American College of Rheumatology total score, seropositivity for dsDNA and RNP antibodies, increased disease duration (odds ratio (OR) = 1.2; 95% confidence interval (CI) of 1.0–1.3, p = 0.04), seropositivity for anti-RNP (OR = 24.4; 95% CI of 1.6–384.0, p = 0.02), and a history of serositis were significantly associated with SLS when compared with symptomatic controls. Conclusion: Respiratory symptoms, abnormal lung function, and SLS are common in SLE. Clinicians should consider evaluation for SLS among symptomatic patients with long-standing disease and a history of pleuritis.

Ultrasound M-mode assessment of diaphragmatic kinetics by anterior transverse scanning in healthy subjects

The purpose of this study was to set an effective standardized method to assess diaphragmatic kinetics by ultrasound. Forty healthy volunteers were submitted to a B- and M-mode ultrasound study using a convex transducer positioned in the subcostal anterior area for transverse scanning. Ultrasound examination was completed in 38/40 cases (95%), spending on average <10 min for examination. The resting and forced diaphragmatic excursions were 18.4 ± 7.6 and 78.8 ± 13.3 mm, respectively, unrelated to demographic or anthropometric parameters: intraobserver variability on three successive measurements resulted in 6.0% and in 3.9%, respectively. An inexperienced sonographer completed the ultrasound examination in 37/40 cases, spending on average >15 min, with significant, although marginal, interobserver variability (31.9% and 14.7% for resting and forced diaphragmatic excursion, respectively). Bedside ultrasonography by an anterior subcostal transverse scanning on semi-recumbent patient proves to be a safe, feasible, reliable, fast, relatively easy and reproducible way to assess diaphragm movement.

Comparação entre inspirometria de incentivo e pressão positiva expiratória na função pulmonar após cirurgia bariátrica

O objetivo deste estudo foi comparar o efeito da pressão positiva expiratória (EPAP, na sigla em inglês) e da inspirometria de incentivo a fluxo sobre a função pulmonar após o bypass gástrico em Y de Roux por videolaparoscopia. Participaram 28 mulheres, não-tabagistas e não-pneumopatas, com índice de massa corporal entre 35 e 50 kg/m², submetidas à cirurgia bariátrica. Todas foram avaliadas por espirometria, cirtometria toracoabdominal e quanto à mobilidade diafragmática no pré e segundo dia de pós-operatório (o tempo de internação foi de 2 dias). Foram divididas em dois grupos, GI - grupo inspirômetro (n=13) e GE, grupo EPAP (n=15). A fisioterapia foi iniciada no dia da cirurgia, cada técnica, inspirometria ou EPAP, com duração de 15 minutos; a fisioterapia motora foi padronizada para ambos os grupos. No pós-operatório, houve redução similar nos dois grupos das variáveis: capacidade vital, volume de reserva inspiratório, capacidade vital forçada e ventilação voluntária máxima. Não houve alteração nos valores do volume corrente no GI e volume de reserva expiratório no GE. A mobilidade diafragmática e a mobilidade toracoabdominal foram menos prejudicadas no GI. No pós-operatório da cirurgia bariátrica por videolaparoscopia, a inspirometria de incentivo a fluxo exerceu melhores efeitos na manutenção do volume corente, na mobilidade diafragmática e toracoabdominal, enquanto a EPAP foi mais eficaz no restabelecimento do volume de reserva expiratório.

Diaphragmatic motion studied by m-mode ultrasonography: methods, reproducibility, and normal values

BACKGROUND

Although diaphragmatic motion is readily studied by ultrasonography, the procedure remains poorly codified. The aim of this prospective study was to determine the reference values for diaphragmatic motion as recorded by M-mode ultrasonography.

METHODS

Two hundred ten healthy adult subjects (150 men, 60 women) were investigated. Both sides of the posterior diaphragm were identified, and M-mode was used to display the movement of the anatomical structures. Examinations were performed during quiet breathing, voluntary sniffing, and deep breathing. Diaphragmatic excursions were measured from the M-mode sonographic images. In addition, the reproducibility (inter- and intra-observer) was assessed.

RESULTS

Right and left diaphragmatic motions were successfully assessed during quiet breathing in all subjects. During voluntary sniffing, the measurement was always possible on the right side, and in 208 of 210 volunteers, on the left side. During deep breathing, an obscuration of the diaphragm by the descending lung was noted in subjects with marked diaphragmatic excursion. Consequently, right diaphragmatic excursion could be measured in 195 of 210 subjects, and left diaphragmatic excursion in only 45 subjects. Finally, normal values of both diaphragmatic excursions were determined. Since the excursions were larger in men than in women, the gender should be taken into account. The lower limit values were close to 0.9 cm for women and 1 cm for men during quiet breathing, 1.6 cm for women and 1.8 cm for men during voluntary sniffing, and 3.7 cm for women and 4.7 cm for men during deep breathing.

CONCLUSIONS

We demonstrated that M-mode ultrasonography is a reproducible method for assessing hemidiaphragmatic movement.

Association of the shrinking lung syndrome in systemic lupus erythematosus with pleurisy: a systematic review

OBJECTIVES

To report 2 patients with systemic lupus erythematosus and typical shrinking lung syndrome (SLS) in which pleuritic chest pain was the predominant symptom. In addition, to record the prevalence of pleuritic chest pain in all reported cases of patients with SLS and diaphragmatic dysfunction.

METHODS

We conducted a comprehensive search of the English literature to record the association of pleurisy and SLS in all reported cases using the MEDLINE database from 1965 to present.

RESULTS

Of the 77 patients with SLS reported in the literature, 50 (65%) patients had pleuritic chest pain at the time of evaluation. Treatment with anti-inflammatory agents improved symptoms in the majority of cases.

CONCLUSIONS

Pleuritic inflammation and pain may have an important role in the pathogenesis of SLS. A possible mechanism linking pleural inflammation and diaphragm dysfunction may be via a reflex inhibition of diaphragmatic activation.

Air trapping: The major factor limiting diaphragm mobility in chronic obstructive pulmonary disease patients

BACKGROUND AND OBJECTIVE

Patients with COPD can have impaired diaphragm mechanics. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. This study evaluated the relationship between pulmonary function and diaphragm mobility, as well as that between respiratory muscle strength and diaphragm mobility, in COPD patients.

METHODS

COPD patients with pulmonary hyperinflation (n = 54) and healthy subjects (n = 20) were studied. Patients were tested for pulmonary function, maximal respiratory pressures and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein.

RESULTS

COPD patients had less diaphragm mobility than did healthy individuals (36.5 +/- 10.9 mm vs 46.3 +/- 9.5 mm, P = 0.001). In COPD patients, diaphragm mobility correlated strongly with pulmonary function parameters that quantify air trapping (RV: r = -0.60, P < 0.001; RV/TLC: r = -0.76, P < 0.001), moderately with airway obstruction (FEV(1): r = 0.55, P < 0.001; airway resistance: r = -0.32, P = 0.02) and weakly with pulmonary hyperinflation (TLC: r = -0.28, P = 0.04). No relationship was observed between diaphragm mobility and respiratory muscle strength (maximal inspiratory pressure: r = -0.11, P = 0.43; maximal expiratory pressure: r = 0.03, P = 0.80).

CONCLUSION

The results of this study suggest that the reduction in diaphragm mobility in COPD patients is mainly due to air trapping and is not influenced by respiratory muscle strength or pulmonary hyperinflation.

Avaliação ultra-sonográfica da mobilidade do diafragma em diferentes posturas em sujeitos saudáveis

OBJETIVO: Avaliar, por meio de ultra-sonografia, o efeito da mudança de posicionamento corporal na mobilidade diafragmática de sujeitos saudáveis durante a respiração espontânea. MÉTODOS: Foram avaliadas sete mulheres voluntárias, saudáveis, sem histórico clínico de doenças cárdio-respiratórias, não tabagistas e eutróficas. Os sujeitos foram submetidos à prova de função pulmonar e à avaliação ultra-sonográfica da mobilidade do diafragma direito através do deslocamento crânio-caudal do ramo esquerdo da veia porta, utilizando-se um aparelho de ultra-sonografia no modo B. A mobilidade do diafragma direito foi avaliada em decúbito lateral direito e em decúbito lateral esquerdo, e a ordem de avaliação das posturas foi definida aleatoriamente por meio de um sorteio prévio. RESULTADOS: A média da excursão do diafragma direito em decúbito lateral direito (51,30 ± 9,69 mm) foi significativamente maior (p = 0,03) que em decúbito lateral esquerdo (45,93 ± 10,37 mm). CONCLUSÃO: Os resultados sugerem que, durante a ventilação espontânea, a mobilidade da porção dependente do diafragma é maior do que a da não dependente e que a técnica empregada foi sensível para detectar variações da mobilidade do diafragma com as mudanças de posicionamento.

Left hemidiaphragmatic mobility: assessment with ultrasonographic measurement of the craniocaudal displacement of the splenic hilum and the inferior pole of the spleen

OBJECTIVE

The purpose of this study was to evaluate the correlation between the radiographic and ultrasonographic measurements of craniocaudal displacement of the left hemidiaphragm.

METHODS

Forty-nine patients with clinical indications for interventional procedures prospectively underwent radiographic evaluation of left hemidiaphragmatic mobility and B-mode ultrasonographic measurement of craniocaudal displacement of the hilum and the inferior pole of the spleen. Ultrasonography was performed with a 3.5-MHz convex transducer in a left intercostal position under a longitudinal orientation. Statistical analyses were performed with linear regression, a paired Student t test, and Bland-Altman analyses.

RESULTS

The correlation between the craniocaudal splenic hilum displacement and radiographic measurements was found to be linear: hemidiaphragmatic mobility = 17.795 + 0.429 x splenic hilum displacement (SE for the regression coefficient = 0 .12; P = .0012), although the values obtained with both methods were statistically different (P < .05). The same results could be observed with the use of the inferior pole of the spleen: hemidiaphragmatic mobility = 9.5596 + 0.5455 x inferior polo displacement (SE for the regression coefficient = 0 .11; P < .0001). The mean difference between the values obtained by ultrasonography and by radiography was statistically significant (16.7 +/- 16.1 mm; P < .05 [hilum]; 18.9 +/- 14.2 mm; P < .05 [inferior pole]).

CONCLUSIONS

These results allow us to conclude that ultrasonography can be used as an alternative method for left hemidiaphragm mobility evaluation compared with radiography.

Comparison of ultrasonographic renal excursion to fluoroscopic diaphragmatic excursion for the assessment of diaphragmatic function in patients with high cervical cord injury11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organizations with which the author(s) are associated

OBJECTIVE

To compare the renal excursion detected by ultrasonography with the diaphragmatic excursion recorded by fluoroscopy in estimating the diaphragmatic function in patients with high cervical cord injury.

DESIGN

Prospective, blinded comparative study.

SETTING

A rehabilitation hospital affiliated with a medical university.

PARTICIPANTS

Fifteen consecutively admitted patients with high cervical cord injury.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Chest radiographs, fluoroscopy of diaphragmatic motion, and ultrasonography of renal motion.

RESULT

Of the 15 patients, 2 were diagnosed with hemidiaphragm paralysis using fluoroscopy and renal ultrasonography. The average diaphragmatic excursion was 59 mm (range, 30-83 mm) in 28 nonparalyzed hemidiaphragms. The average renal excursion was 49 mm (range, 28-61 mm). The correlation coefficient for fluoroscopic hemidiaphragm excursion and ultrasonographic renal excursion was .853.

CONCLUSION

Ultrasonographic renal excursion and fluoroscopic diaphragmatic excursion correlated highly. With the fluoroscopy results as the criterion standard, the diagnostic sensitivity and specificity were both 100% for renal sonography. With the advantages of convenience of use, no radiation exposure, and high reproducibility, renal ultrasonography is recommended as a first-line screening and long-term follow-up tool for assessment of diaphragmatic function.