Depth of cervical plexus block and phrenic nerve blockade: a randomized trial

Background and objectivesCervical plexus blocks are commonly used to facilitate carotid endarterectomy (CEA) in the awake patient. These blocks can be divided into superficial, intermediate, and deep blocks by their relation to the fasciae of the neck. We hypothesized that the depth of block would have a significant impact on phrenic nerve blockade and consequently hemi-diaphragmatic motion.MethodsWe enrolled 45 patients in an observer blinded randomized controlled trial, scheduled for elective, awake CEA. Patients received either deep, intermediate, or superficial cervical plexus blocks, using 20 mL of 0.5% ropivacaine mixed with an MRI contrast agent. Before and after placement of the block, transabdominal ultrasound measurements of diaphragmatic movement were performed. Patients underwent MRI of the neck to evaluate spread of the injectate, as well as lung function measurements. The primary outcome was ipsilateral difference of hemi-diaphragmatic motion during forced inspiration between study groups.ResultsPostoperatively, forced inspiration movement of the ipsilateral diaphragm (4.34±1.06, 3.86±1.24, 2.04±1.20 (mean in cm±SD for superficial, intermediate and deep, respectively)) was statistically different between block groups (p<0.001). Differences were also seen during normal inspiration. Lung function, oxygen saturation, complication rates, and patient satisfaction did not differ. MRI studies indicated pronounced permeation across the superficial fascia, but nevertheless easily distinguishable spread of injectate within the targeted compartments.ConclusionsWe studied the characteristics and side effects of cervical plexus blocks by depth of injection. Diaphragmatic dysfunction was most pronounced in the deep cervical plexus block group.Trial registration numberEudraCT 2017-001300-30.

Diaphragmatic Point-of-Care Ultrasound in COVID-19 Patients in the Emergency Department—A Proof-of-Concept Study

Background: Lung Ultrasound Evaluation (LUS) is usefully applied in the Emergency Department (ED) to patients with suspected or confirmed COVID-19. Diaphragmatic Ultrasound (DUS) may provide additional insight into ventilatory function. This proof-of-concept study aimed to evaluate the feasibility of LUS and DUS in a third level ED during the COVID-19 pandemic. Methods: Adult patients presenting with COVID-19 symptoms were eligible. After the physical examination, both LUS and DUS (i.e., diaphragmatic motion and thickness) were performed. All patients were followed after 30 days to determine their need for ventilation, admission, and/or a new ED evaluation after discharge. The diagnostic accuracies of diaphragm measurements in assessing the risk of the 30-day outcome were calculated as well as the measurements’ usefulness. Bland–Altman plots were used for comparing bedside and off-line diaphragm measurements. Results: 118 patients were enrolled. Median thickness and motion were 1.7 mm (iqr 0.4) and 1.8 cm (iqr 0.7), respectively, with a mean difference of 0.009 mm (95% CI −0.037–0.056 mm) and −0.051 cm (95% CI −0.108–0.006 cm), respectively. The 30-day outcome was associated with an increase in thickness (OR 5.84, 95% CI 0.96–35.4), and a lower motion (OR 0.49, 95% CI 0.2–1.21). Conclusion: DUS seemed to be feasible and reliable in the ED in a population of patients presenting with symptoms related to COVID-19 infection.

The Diagnosis of Unilateral Diaphragmatic Paralysis Using M-mode: A Case Report from Palestine

Background: Diaphragmatic paralysis is one the causes of dyspnoea and difficulty in breathing. There are many causes of diaphragmatic paralysis, especially trauma and iatrogenic injury of phrenic nerve. Usually, diaphragmatic paralysis diagnosis depends on fluoroscopic examination of diaphragmatic displacement during sharp sniffs. However, due to disadvantages of fluoroscopic examination, the trend for less radiation examination by using ultrasound is increasing especially using M-mode for detection of diaphragmatic motion during respiration. Case: A new-born baby boy with uneventful pregnancy and normal delivery with good general condition, developed severe respiratory distress at 3rd day of life and was diagnosed to have bilateral pneumothorax. Bilateral chest tubes were inserted with improvement of his condition. The baby then started to develop desaturation with serial chest x-rays done and showed elevated left hemi-diaphragm. Suspicion toward left hemi-diaphragm paralysis increased and due to his general condition, fluoroscopic examination was difficult. So that, Ultrasound with M-mode was used with diagnosis of the patient with left hemi-diaphragmatic paralysis. Conclusion: Ultrasound and the using of M-mode in detection of diaphragmatic motion is one of the most important and applicable diagnostic procedure for diagnosis of diaphragmatic weakness and paralysis.

CT-derived 3D-diaphragm motion in emphysema and IPF compared to normal subjects

Image registration-based local displacement analysis enables evaluation of respiratory motion between two computed tomography-captured lung volumes. The objective of this study was to compare diaphragm movement among emphysema, idiopathic pulmonary fibrosis (IPF) and normal subjects. 29 normal, 50 emphysema, and 51 IPF subjects were included. A mass preserving image registration technique was used to compute displacement vectors of local lung regions at an acinar scale. Movement of the diaphragm was assumed to be equivalent to movement of the basal lung within 5 mm from the diaphragm. Magnitudes and directions of displacement vectors were compared between the groups. Three-dimensional (3D) and apico-basal displacements were smaller in emphysema than normal subjects (P = 0.003, P = 0.002). Low lung attenuation area on expiration scan showed significant correlations with decreased 3D and apico-basal displacements (r = − 0.546, P < 0.0001; r = − 0.521, P < 0.0001) in emphysema patients. Dorsal–ventral displacement was smaller in IPF than normal subjects (P < 0.0001). The standard deviation of the displacement angle was greater in both emphysema and IPF patients than normal subjects (P < 0.0001). In conclusion, apico-basal movement of the diaphragm is reduced in emphysema while dorsal–ventral movement is reduced in IPF. Image registration technique to multi-volume CT scans provides insight into the pathophysiology of limited diaphragmatic motion in emphysema and IPF.

Diaphragmatic motion recorded by M-mode ultrasonography: limits of normality

BackgroundChest ultrasonography has proven to be useful in the diagnosis of diaphragm dysfunction. The aim of the present study was to determine the normal values of the motion of both hemidiaphragms recorded by M-mode ultrasonography.MethodsHealthy volunteers were studied while in a seated position. Diaphragmatic excursions and diaphragm profiles were measured during quiet breathing, voluntary sniffing, and deep breathing. Diaphragmatic excursions were assessed by M-mode ultrasonography, using an approach perpendicular to the posterior part of the diaphragm. Anatomical M-mode was used for the recording of the complete excursion during deep breathing.ResultsThe study included 270 men and 140 women. The diaphragmatic motions during quiet breathing and voluntary sniffing were successfully recorded in all of the participants. The use of anatomical M-mode was particularly suitable for measurement of the entire diaphragmatic excursion during deep breathing. The statistical analysis showed that the diaphragmatic excursions were larger in men compared to women, supporting the determination of normal values based on gender. The lower and upper limits of normal excursion were determined for men and women for both hemidiaphragms during the three maneuvers that were investigated. The lower limits of normal diaphragmatic excursions during deep breathing should be used to detect diaphragmatic hypokinesia, i.e., 3.3 and 3.2 cm in women and 4.1 and 4.2 cm in men for the right and the left sides, respectively.ConclusionThe normal values of the diaphragmatic motion and the lower and upper limits of normal excursion can be used by clinicians to detect diaphragmatic dysfunction.

An Osteopathic Approach to Traumatically Induced Mechanical Dyspnea: A Case Report

Mechanical dyspnea (breathing pattern disorders), such as hyperventilation or hypoventilation, can result in increased pain and have negative mechanical, psychological, emotion, and biochemical effects.1,2,3 Proper breathing helps to stabilize the spine, maintain posture, and decrease anxiety. Injuries to the abdominal and pelvic diaphragms can disrupt proper breathing mechanics, leading to increased pain, anxiety, poor posture, and poor spinal and overall body mechanics. Osteopathic manipulative treatment can help restore proper diaphragmatic motion and proper breathing mechanics as the present case will demonstrate.