Hemidiaphragmatic Movement Research Articles

The Minimum Effective Analgesic Volume of 0.5% Bupivacaine for Ultrasound-Guided Anterior Suprascapular Nerve Block.

Objective The interscalene brachial plexus block (ISBB) constitutes the gold standard for analgesia after shoulder procedures. Ipsilateral phrenic nerve block remains the most common adverse effect after ISBB. Alternative nerve blocks are performed in shoulder surgery in order to prevent hemi-diaphragmatic paralysis (HDP). The purpose of the present study was to investigate the minimum effective local anesthetic volume of 0.5% bupivacaine for postoperative analgesia with an anterior suprascapular nerve block (ASSB). The secondary aim was to investigate diaphragm functions with the local anesthetic doses used while conducting effective volume research. Method This prospective observational study was conducted at the American Hospital of Istanbul, Turkey, from March to July 2022. The initial injected volume of 0.5% bupivacaine was 10 ml. Our clinical experience indicates that this yields a complete sensory block of the anterior suprascapular nerve. In accordance with the up-and-down method, the volume of 0.5% bupivacaine used for a particular patient was determined by the outcome of the preceding block, which represented block success. In case of effective ASSB being achieved, the volume of 0.5% bupivacaine to be administered to the next patient was lowered by 1 ml. In case of block failure, however, the volume of 0.5% bupivacaine to be applied in the subsequent case was increased by 1 ml. Ipsilateral hemi-diaphragmatic movement measurements were taken before (baseline) and 30 minutes after the block. General anesthesia was induced 60 minutes after the completion of the block performance by means of a standardized protocol. Results Sixty-seven patients were included in the study. The ED50 and ED95 calculated for anterior suprascapular nerve block using probit transformation and logistic regression analysis were 2.646 (95% CI, 0.877-2.890) and 3.043 ml (95% CI, 2.771-4.065), respectively. When complete paralysis was defined as 75% or above, partial paralysis as 25-50%, and no paralysis as 25% or less, volumes of 6 ml or lower appeared to cause no paralysis for the anterior suprascapular nerve block. Conclusion We, therefore, recommend using a volume of 6 ml or less in order to achieve diaphragm-sparing features for anterior suprascapular nerve blocks.

Ultrasound Evaluation of Hemidiaphragm Function Following Thoracentesis: A Study on Mechanisms of Dyspnea Related to Pleural Effusion.

Dyspnea is the major symptom caused by pleural effusion. The pathophysiological pathways leading to dyspnea are poorly understood. Dysfunction of respiratory mechanics may be a factor. We aimed to study the change in diaphragmatic function following thoracentesis. Patients undergoing thoracentesis at a highly specialized pleural center, underwent ultrasound evaluation of hemidiaphragm movement, before and after thoracentesis was performed. The change was compared to the reduction of dyspnea measured at the modified Borg scale. Thirty-two patients were included. Dyspnea was reduced from 5.01 [95% confidence interval (CI): 4.12-6.04] to 2.6 (95% CI: 1.87-3.4, P<0.0001). Low hemidiaphragmatic movement before thoracentesis on the side of pleural effusion was improved by 17.4 cm (95% CI: 13.04-21.08), equalizing movement to the side without pleural effusion. On average, 1283 mL (SD: 469) fluid was drained. Multiple linear regression analysis showed that prethoracentesis ultrasound evaluation of hemidiaphragmatic function was correlated with successful thoracentesis. Hemidiaphragm function is reduced on the side of pleural effusion, and thoracentesis restores function. Improvement in diaphragm movement is related to a reduction in dyspnea.

Using M-mode ultrasonography to assess diaphragm dysfunction and predict the success of mechanical ventilation weaning in elderly patients.

Ultrasonography (US) is a non-invasive and commonly available bedside diagnostic tool. The aim of this study was to assess the utility of M-mode US on ventilator weaning outcomes in elderly patients. This was a single center, prospective, observational study in patients aged 80 years or older who were in the medical intensive care unit, had undergone mechanical ventilation for >48 hours, and met the criteria for a spontaneous breathing trial (SBT). For 30 minutes at the start of SBT, each hemi-diaphragmatic movement and the velocity of contraction were evaluated by M-mode US. The the area under the receiver operating characteristic curve (AUROC) was calculated to determine the ability for measured variables to predict successful ventilator weaning. Forty patients were enrolled and assessed, grouped by those who had US-diagnosed diaphragm dysfunction (DD; 30/40; 75%) and those who did not (10/40; 25%). Patients with DD had a significantly longer total mechanical ventilation duration (536.4±377.05 vs. 250±109.02 hours, P=0.02) and weaning time (425.9±268.31 vs. 216.0±134.22 hours, P=0.002) than patients without DD. Patients with DD also had a higher incidence of weaning failure than patients without DD (24/30 vs. 4/10, P=0.017). Analysis of the receiver operating characteristic (ROC) curve (ROC) curve showed that the optimal cut-off values to predict weaning success were >10.7 mm for the right diaphragmatic movement, and >21.32 mm/s for the right diaphragmatic velocity of contraction; AUROC were 0.839 (95% CI, 0.689-0.936) and 0.833 (95% CI, 0.682-0.932), respectively. The sensitivity, specificity, positive and negative likelihood ratios for predicting weaning success were 83.33% vs. 66.67%, 75.00% vs. 92.86%, 3.33 vs. 9.33, and 0.22 vs. 0.36, for right diaphragmatic movement and diaphragmatic contraction velocity, respectively. When assessed by M-mode US, DD appeared to be common in ventilated patients aged 80 years or older and was associated with a higher incidence of weaning failure. Larger right diaphragmatic movements or faster right diaphragmatic contraction velocity appeared to be good predictors of mechanical ventilation weaning success in elderly patients.

Sonographic evaluation of diaphragmatic dysfunction in COPD patients

BackgroundDiaphragmatic dysfunction is an important reason for dyspnea in COPD patients. But diaphragmatic dysfunction is difficult to evaluate. Ultrasound is an option. We measure sonographically the up- and downward movement of the lung silhouette on both hemidiaphragms. The aim of this prospective investigation was to compare this method with another sonographic method that visualizes the right hemidiaphragm directly and to compare the sonographic results with lung function parameters.Methods and patientsEighty participants – 20 healthy persons and 60 COPD patients – three groups each with 20 patients with COPD GOLD II, III, and IV – were investigated. The sonographic measurements of the diaphragms were performed. Lung function parameters, blood gases, and 6-minute walk test were also collected and compared to the sonographic results.ResultsThe sonographic measurement of the lung silhouette was easy to perform in all study participants. The correlation between the sonographic methods measuring the right hemidiaphragmatic movement was strong (r=0.85). There was also a strong correlation between the demonstrated sonographic measurement of the up- and downward movement of the lung silhouette and the forced expiratory volume in the first second (r=0.83).ConclusionWe demonstrated that the sonographic measurement of the movement of the lung silhouette is an easy way to establish diaphragmatic dysfunction in COPD patients; it can be done in all patients with reliable results for the right and the left hemidiaphragm.

Minimum Effective Volume of Local Anesthetic for Shoulder Analgesia by Ultrasound-Guided Block at Root C7 With Assessment of Pulmonary Function

This study was performed to determine the minimum effective volume of ropivacaine 0.75% required to produce effective shoulder analgesia for an ultrasound (US)-guided block at the C7 root level with assessment of pulmonary function. Using the Dixon and Massey up-and-down method study design, 20 patients scheduled for elective open shoulder surgery under combined general anesthesia and continuous interscalene brachial plexus block were included. Initial volume of ropivacaine 0.75% was 6 mL; block success or failure determined a 1-mL decrease or increase for the subsequent patient, respectively. General anesthesia was standardized. A continuous infusion of ropivacaine 0.2% was started at a rate of 6 mL/hr at 2 hrs after completion of surgery. Ventilatory function was assessed using spirometry, and movement of the hemidiaphragm was assessed by US. The minimum effective volume of local anesthetic in 50% and 95% of the patients was 2.9 mL (95% confidence interval, 2.4-3.5 mL) and 3.6 mL (95% confidence interval, 3.3-6.2 mL), respectively. Ventilatory function and hemidiaphragmatic movement was not reduced up to and including 2 hrs after completion of surgery, but 22 hrs after start of the continuous infusion of ropivacaine 0.2%, ventilatory function and hemidiaphragmatic movement were significantly reduced (P < 0.001). The minimum effective volume of local anesthetic for shoulder analgesia for a US-guided block at the C7 root level in 50% and 95% of the patients was 2.9 and 3.6 mL, respectively. Pulmonary function was unchanged until 2 hrs after completion surgery, but reduced 22 hrs after start of a continuous infusion of ropivacaine 0.2%.

Hemidiaphragmatic Paresis Can Be Avoided in Ultrasound-Guided Supraclavicular Brachial Plexus Block

Supraclavicular brachial plexus block is associated with 50% to 67% incidence of hemidiaphragmatic paresis as a result of phrenic nerve block. We examined whether ultrasound-guided compared with nerve stimulation supraclavicular brachial plexus block using 0.75% ropivacaine results in a lower incidence of hemidiaphragmatic paresis. In a prospective randomized observer-blinded controlled trial, 60 patients scheduled for elective elbow, forearm, wrist, or hand surgery under supraclavicular brachial plexus block without sedation were included. Supraclavicular brachial plexus block was performed with 20 mL of 0.75% ropivacaine using either ultrasound or nerve stimulation guidance. Ventilatory function was assessed by ultrasound examination of hemidiaphragmatic movement and spirometry. None of the 30 patients in the ultrasound group showed complete or partial paresis of the hemidiaphragm (95% confidence interval, 0.00-0.14), whereas in the nerve stimulation group, 15 patients showed complete paresis of the hemidiaphragm and 1 patient showed partial paresis of the hemidiaphragm (0% versus 53%, respectively; P < 0.0001). Ventilatory function (forced expiratory volume 1, forced vital capacity, peak expiratory flow) was significantly reduced in the nerve stimulation group compared with the ultrasound-guided group (P < 0.05). Two block failures occurred in the nerve stimulation group compared with none in the ultrasound group (P = 0.49). No adverse effects occurred in either group. Ultrasound-guided supraclavicular brachial plexus block, using 20 mL of 0.75% ropivacaine with the described technique, is not associated with hemidiaphragmatic paresis.

Diaphragmatic Motion Studied by M-Mode Ultrasonography: Methods, Reproducibility, and Normal Values

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

Ultrasonic assessment of hemidiaphragmatic movement: An indirect method of evaluating mediastinal invasion in non-small cell lung cancer

Ultrasonic assessment of hemidiaphragmatic movement: An indirect method of evaluating mediastinal invasion in non-small cell lung cancer

Comparison of ultrasound with fluoroscopy in the Assessment of suspected hemidiaphragmatic movement abnormality

A comparative study of quantitative hemidiaphragmatic ultrasound with fluoroscopy was undertaken in 30 patients referred for investigation of suspected hemidiaphragmatic movement abnormality. The aim of this study was to determine whether assessment with ultrasound or fluoroscopy differed, and which technique appeared more suitable in the investigation of hemidiaphragmatic movement disorder. There were four technical failures using fluoroscopy (13%), compared with none using ultrasound. Using the normal ranges of right to left ratio of maximal excursion (0.5-2.0 for fluoroscopy and 0.5-1.6 for ultrasound) there was concordance in 21 out of 26 (81%) patients. All cases of abnormality on fluoroscopy were seen on ultrasound. Four of the discordant cases had excursions on the lesser side in the normal range on ultrasound suggesting a milder movement abnormality detected by ultrasound than by fluoroscopy. Sniff testing conferred no advantage over quantitative testing. Ultrasound has technical, qualitative and quantitative advantages over fluoroscopy and should be the method of choice in the investigation of suspected hemidiaphragmatic movement abnormality.

Ultrasound assessment of normal hemidiaphragmatic movement: relation to inspiratory volume.

Traditionally the radiological assessment of diaphragmatic movement has relied on fluoroscopy. Ultrasound scanning has recently been shown to be a sensitive and reproducible method of assessing hemidiaphragmatic movement in normal subjects. A study was undertaken to examine how movement of the diaphragm measured by ultrasound scanning relates to inspired lung volumes measured by spirometric testing. Ultrasound examinations were performed on 14 normal volunteers using a 3.5 MHz sector transducer (Acuson 128). A fixed skin position on each lateral chest wall between the anterior clavicular and midaxillary line was selected symmetrically to obtain a longitudinal plane of each hemidiaphragm including the maximal renal bipolar length, allowing identification of the adjacent posterior aspect of the diaphragm. Craniocaudal excursions of the posterior part of each hemidiaphragm on successive respiratory cycles were recorded on videotape and compared with spirometric measurements recorded simultaneously on a water bath spirometer. Measurements were made in the sitting and supine position and were repeated on a separate occasion (at least two weeks apart) in 10 subjects by the same operator to assess reproducibility. The relation between inspired volume and hemidiaphragmatic movement was found to be linear. The gradient of these observed linear relations (hemidiaphragmatic excursion (mm)/inspired volume (1)) was calculated and their distribution for each hemidiaphragm followed a normal distribution irrespective of position. The 95% confidence limits of the right to left ratio of these gradients in the supine position were 0.53 and 1.7. Change of posture from the supine to the sitting position reduced the gradient. The technique had acceptable reproducibility with coefficients of variation for the supine position of 7.5% and 11.7% for right and left hemidiaphragm respectively. Ultrasound scanning is a simple, non-invasive and reproducible means of assessing hemidiaphragmatic movement, yielding quantitative information which relates to inspired lung volumes.

Technical report: Quantitative assessment of diaphragmatic movement — A reproducible method using ultrasound

We report a reproducible ultrasound technique used to determine normal range of excursion and the variability of hemidiaphragmatic movement.