Diaphragmatic Palsy

Ultrasound assessment of diaphragmatic dysfunction in non-critically ill patients: relevant indicators and update

Diaphragm dysfunction (DD) can be classified as mild, resulting in diaphragmatic weakness, or severe, resulting in diaphragmatic paralysis. Various factors such as prolonged mechanical ventilation, surgical trauma, and inflammation can cause diaphragmatic injury, leading to negative outcomes for patients, including extended bed rest and increased risk of pulmonary complications. Therefore, it is crucial to protect and monitor diaphragmatic function. Impaired diaphragmatic function directly impacts ventilation, as the diaphragm is the primary muscle involved in inhalation. Even unilateral DD can cause ventilation abnormalities, which in turn lead to impaired gas exchange, this makes weaning from mechanical ventilation challenging and contributes to a higher incidence of ventilator-induced diaphragm dysfunction and prolonged ICU stays. However, there is insufficient research on DD in non-ICU patients, and DD can occur in all phases of the perioperative period. Furthermore, the current literature lacks standardized ultrasound indicators and diagnostic criteria for assessing diaphragmatic dysfunction. As a result, the full potential of diaphragmatic ultrasound parameters in quickly and accurately assessing diaphragmatic function and guiding diagnostic and therapeutic decisions has not been realized.

Efficacy and safety of extrafascial injection versus intrafascial injection for interscalene brachial plexus block: a systematic review and meta-analysis

INTRODUCTION

This systematic review and meta-analysis aimed to assess the efficacy and safety of interscalene brachial plexus block (ISB) techniques in upper limb and shoulder surgeries.

EVIDENCE ACQUISITION

We conducted a comprehensive search of PubMed, Web of Science, Cochrane Central Register of Controlled Trials, Embase, Medline, and Scopus databases up to May 14th, 2023. We employed a search strategy involving keywords such as "brachial plexus block," "interscalene brachial plexus block," "ISB," "extrafascial," and "intrafascial," without applying search restrictions or filters. Eligible studies consisted of randomised controlled trials (RCTs) that compared extrafascial and intrafascial ISB techniques in adult patients undergoing upper limb and shoulder surgeries.

EVIDENCE SYNTHESIS

Our analysis included six RCTs encompassing 485 participants. Extrafascial injection demonstrated superiority over intrafascial injection in reducing the incidence of hemidiaphragmatic paresis (RR 0.33, 95% CI 0.124 to 0.47, P<0.00001) and preserving respiratory function (MS 0.31, 95% CI 0.1 to 0. 52, P=0.003 FEV1 in liters). Additionally, extrafascial ISB exhibited a lower risk of block-related complications (RR 0.35, 95% CI 0.25 to 0.50, P<0.00001). However, the intrafascial technique offered a faster sensory and motor block onset. The duration of sensory block did not significantly differ. The incidence of Horner syndrome showed no statistically significant difference.

CONCLUSIONS

Our findings favor extrafascial ISB techniques because they reduce hemidiaphragmatic paresis, preserve respiratory function, and lower block-related complications. However, further research is necessary to establish their safety and efficacy in specific patient populations.

Approach to Acute Traumatic and Nontraumatic Diaphragmatic Abnormalities

Acute diaphragmatic abnormalities encompass a broad variety of relatively uncommon and underdiagnosed pathologic conditions, which can be subdivided into nontraumatic and traumatic entities. Nontraumatic abnormalities range from congenital hernia to spontaneous rupture, endometriosis-related disease, infection, paralysis, eventration, and thoracoabdominal fistula. Traumatic abnormalities comprise both blunt and penetrating injuries. Given the role of the diaphragm as the primary inspiratory muscle and the boundary dividing the thoracic and abdominal cavities, compromise to its integrity can yield devastating consequences. Yet, diagnosis can prove challenging, as symptoms may be vague and findings subtle. Imaging plays an essential role in investigation. Radiography is commonly used in emergency evaluation of a patient with a suspected thoracoabdominal process and may reveal evidence of diaphragmatic compromise, such as abdominal contents herniated into the thoracic cavity. CT is often superior, in particular when evaluating a trauma patient, as it allows rapid and more detailed evaluation and localization of pathologic conditions. Additional modalities including US, MRI, and scintigraphy may be required, depending on the clinical context. Developing a strong understanding of the acute pathologic conditions affecting the diaphragm and their characteristic imaging findings aids in efficient and accurate diagnosis. Additionally, understanding the appearance of diaphragmatic anatomy at imaging helps in differentiating acute pathologic conditions from normal variations. Ultimately, this knowledge guides management, which depends on the underlying cause, location, and severity of the abnormality, as well as patient factors. ©RSNA, 2024 Supplemental material is available for this article.

Bilateral Phrenic Nerve Palsy Associated With Neuralgic Amyotrophy

Neuralgic amyotrophy (NA) is a multifocal inflammatory neuropathy accompanied by acute pain and muscle atrophy. NA commonly affects the upper extremities, but rarely affects the phrenic nerve. Here, we report a male with neck pain, orthopnea, difficulty sleeping in the supine position, and inability to slurp. His saturated oxygen level decreased from 97% to 86% in the supine position. His right shoulder showed muscle atrophy. Chest X-ray examination in the supine position and a nerve conduction study showed phrenic palsy. We diagnosed it as bilateral phrenic nerve palsy associated with NA. NA sometimes causes phrenic nerve palsy and may cause slurping difficulty.

Perioperative Diaphragm Dysfunction

Diaphragm Dysfunction (DD) is a respiratory disorder with multiple causes. Although both unilateral and bilateral DD could ultimately lead to respiratory failure, the former is more common. Increasing research has recently delved into perioperative diaphragm protection. It has been established that DD promotes atelectasis development by affecting lung and chest wall mechanics. Diaphragm function must be specifically assessed for clinicians to optimally select an anesthetic approach, prepare for adequate monitoring, and implement the perioperative plan. Recent technological advancements, including dynamic MRI, ultrasound, and esophageal manometry, have critically aided disease diagnosis and management. In this context, it is noteworthy that therapeutic approaches for DD vary depending on its etiology and include various interventions, either noninvasive or invasive, aimed at promoting diaphragm recruitment. This review aims to unravel alternative anesthetic and operative strategies that minimize postoperative dysfunction by elucidating the identification of patients at a higher risk of DD and procedures that could cause postoperative DD, facilitating the recognition and avoidance of anesthetic and surgical interventions likely to impair diaphragmatic function.

Association between diaphragmatic dysfunction after adult cardiovascular surgery and prognosis of mechanical ventilation: a retrospective cohort study

BACKGROUND

Diaphragmatic dysfunction often occurs after adult cardiovascular surgery. The prognostic effect of diaphragmatic dysfunction on ventilatory management in patients after cardiovascular surgery is unknown. This study aimed to investigate the association between diaphragmatic dysfunction and prognosis of ventilatory management in adult postoperative cardiovascular surgery patients.

METHODS

This study was a single-center retrospective cohort study conducted at a tertiary care university hospital. This study included adult patients admitted to the intensive care unit under tracheal intubation after cardiovascular surgery. Spontaneous breathing trial was performed, and bilateral diaphragmatic motion was assessed using ultrasonography; diaphragmatic dysfunction was classified as normal, incomplete dysfunction, or complete dysfunction. The primary outcome was weaning off in mechanical ventilation. The duration of mechanical ventilation was defined as duration from the date of ICU admission to the date of weaning off in mechanical ventilation. The secondary outcomes were reintubation, death from all causes, improvement of diaphragm position assessed by chest radiographs. The subdistribution hazard ratio or hazard ratio (HR) with 95% confidence of intervals (CIs) were estimated by Fine-Gray models or Cox proportional hazard models adjusted for potential confounders.

RESULTS

Of 153 patients analyzed, 49 patients (32.0%) had diaphragmatic dysfunction. Diaphragmatic dysfunction consisted of incomplete dysfunction in 38 patients and complete dysfunction in 11 patients. Diaphragmatic dysfunction groups had longer duration of mechanical ventilation (68 h [interquartile range (IQR) 39-114] vs 23 h [15-67], adjusted subdistribution HR 0.63, 95% CIs 0.43-0.92). There was a higher rate of reintubation (12.2% vs 2.9%, univariate logistic regression analysis p = 0.034, unadjusted odds ratio = 4.70, 95% CIs 1.12-19.65), and a tendency to have higher death from all causes in the diaphragmatic dysfunction group during follow-up period (maximum 6.5 years) (18.4% vs 9.6%, adjusted HR 1.64, 95% CIs 0.59-4.53). The time to improvement of diaphragm position on chest radiograph was significantly longer in the diaphragmatic dysfunction group (14 days [IQR 6-29] vs 5 days [IQR 2-10], adjusted subdistribution HR 0.54, 95% CIs 0.38-0.77).

CONCLUSIONS

Diaphragmatic dysfunction after adult cardiovascular surgery was significantly associated with longer duration of mechanical ventilation and higher reintubation.

A Bilateral Diaphragmatic Paralysis Post-COVID-19 Infection: A Case Report and a Review of the Literature

The diaphragm is the essential respiratory muscle, and damage can significantly impede a human's capacity for blood oxygenation. During inspiration, the diaphragm domes permit the pleural cavity to expand. Whenever this process is disrupted, it results in decreased thoracic expansion and, as a result, hypoventilation. The phrenic nerve innervates the diaphragmatic muscle via the cervical nerve roots C3, C4, and C5. Diaphragmatic paralysis is a multifactorial consequence caused by trauma, neurogenic diseases, infections, inflammatory responses, and chest operative surgery, with the last being the most prevalent causative factor. Here, we are describing the case of a 52-year-old male patient who has had ongoing dyspnea for months after contracting COVID-19 in December 2021, despite the remission of his previous COVID-19 pneumonia in 2020. An X-ray of the chest revealed no diaphragm elevation, whereas electromyography verified diaphragm impairment. On the conservative treatment plan, he reported persistent dyspnea following a period of pulmonary rehabilitation. To a lesser extent, it is advised to wait at least one year to see if there is any reinnervation, which could benefit his lung capacity. COVID-19 has been linked to many systematic diseases. As a result, COVID-19 will not be restricted to its inflammatory effect on the lungs. In other words, it is a multi-organ systematic syndrome. One of these effects is diaphragm paralysis, which should be considered a post-COVID-19 disease. However, there is a need for more literature to support physicians as guidelines for neurological conditions related to COVID-19 infection.

Single injection combined suprascapular and axillary nerve block: A randomised controlled non-inferiority trial in healthy volunteers

BACKGROUND

A shoulder block without lung affection is desirable. In this study, we compared a low versus a high volume of a modified supraclavicular brachial plexus block. We hypothesised that a low volume of local anaesthetic would provide non-inferior block success rate with better preserved lung function.

METHODS

Healthy volunteers were randomised to receive ultrasound guided 5 or 20 ml ropivacaine 0.5% at the departure of the suprascapular nerve from the brachial plexus. Primary outcome was successful shoulder block-defined as cutaneous sensory affection of the axillary nerve and motor affection of the suprascapular nerve (>50% reduction in external rotation force measured with dynamometry). We used a non-inferiority margin of 20%. Secondary outcome was change in lung function measured with spirometry.

RESULTS

Thirteen of 16 (81.3%; 95% confidence interval [CI] 57.0% to 93.4%) in the 5 ml group and 15 of 16 (93.8%; 95% CI 71.7% to 98.9%) in the 20 ml group had successful shoulder block (p = .6). The ratio of the event rates of the 20 ml (standard) and 5 ml (intervention) groups was (15/16)/(13/16) = 0.937/0.813 = 1.15 (95% CI 0.88 to 1.51). All mean reductions in lung function parameters were non-significantly lower in the 5 ml group compared with the 20 ml group.

CONCLUSION

For our primary outcome, the 95% CI of the difference of event ratio included the non-inferiority margin. We are therefore unable to conclude that 5 ml LA is non-inferior to 20 ml LA with respect to block success rate.

Sleeve Gastrectomy in a Patient With Left Hemidiaphragm Paralysis: A Case Report

Unilateral diaphragmatic paralysis is a disorder in which one side of the diaphragm loses the capacity to contract to allow for adequate inspiration. The majority of patients suffering from unilateral diaphragmatic paralysis are asymptomatic and do not require treatment. The laparoscopic sleeve gastrectomy (LSG) is the most common bariatric surgical operation. In this case report, I present the case of a 36-year-old male with congenital left hemidiaphragm paralysis who had LSG for the treatment of morbid obesity. This case demonstrates the efficacy and feasibility of LSG in patients with asymptomatic hemidiaphragm paralysis. During surgery, surgeons must pay close attention to a variety of factors, including a stomach fundus that is situated high in a subcostal region with a narrow space to work.

Diaphragm impairment in patients admitted for severe COVID-19

Among patients affected by the virus COVID-19, physicians have observed ventilation disorders. It is relevant to assess neurological involvement, including the role of diaphragmatic function. Its possible impairment could be related to the systemic inflammatory response and disease progression that both typify COVID-19 infection. We distinguished two groups (severe group (SG) and mild group (MG)) according to the severity of respiratory symptomatology. We performed neurophysiological and sonography studies to evaluate the diaphragmatic function. Regarding the sonography variables, we identified statistically significant differences in the right mean diaphragmatic thickness along with the expiration, showing 1.56 mm (SEM: 0.11) in the SG vs 1.92 mm (SEM: 0.19) in the MG (p = 0.042). The contractibility of both hemidiaphragms was 15% lower in the severe group, though this difference is not statistically significant. In our examination of the neurophysiological variables, in the amplitude responses, we observed a greater difference between responses from both phrenic nerves as follows: the raw differences in amplitude were 0.40 μV (SEM: 0.14) in the SG vs 0.35 μV (SEM: 0.19) in the MG and the percentage difference was 25.92% (SEM: 7.22) in the SG vs 16.28% (SEM: 4.38%) in the MG. Although diaphragmatic dysfunction is difficult to detect, our combined functional and morphological approach with phrenic electroneurograms and chest ultrasounds could improve diagnostic sensitivity. We suggest that diaphragmatic dysfunction could play a relevant role in respiratory disturbance in hospitalised patients with severe COVID-19.

Clinical impact of preoperative diaphragm dysfunction on early outcomes and ventilation function in lung transplant: a single-center retrospective study

Background

Clinical impact of preoperative diaphragm dysfunction on lung transplantation has not been studied. We aimed to evaluate how preoperative diaphragm dysfunction affects clinical outcomes and ventilation function after transplantation.

Methods

We retrospectively enrolled 102 patients. Ultrasound for diagnosis of diaphragm dysfunction was performed on all patients both before and after lung transplantation. The primary outcome was to compare prolonged mechanical ventilation after transplantation according to the preoperative diaphragm dysfunction. Secondary outcomes compared global inhomogeneity index and lung volume after transplantation. Multivariate regression analysis were used to evaluate the association between preoperative diaphragm dysfunction and prolonged mechanical ventilation after transplantation.

Results

A total of 33 patients (32.4%) had preoperative diaphragm dysfunction, and half of them (n = 18) recovered their diaphragm function after transplantation. In contrast, 15 patients (45.5%) showed postoperative diaphragm dysfunction. The ratio of prolonged mechanical ventilation after transplantation was significantly higher in the preoperative diaphragm dysfunction group (p = 0.035). The postoperative durations of mechanical ventilation, intensive care unit and hospital stays were higher in the preoperative diaphragm dysfunction group, respectively (p < 0.05). In the multivariate regression analysis, preoperative diaphragm dysfunction was significantly associated with prolonged mechanical ventilation after transplantation (Odds ratio 2.79, 95% confidence interval 1.07–7.32, p = 0.037). As well, the preoperative diaphragm dysfunction group showed more inhomogeneous ventilation (p < 0.05) and lower total lung volume (p < 0.05) after transplantation. In addition, at 1 month and 3 months after transplantation, FVC was significantly lower in the preoperative diaphragm dysfunction group (p < 0.05).

Conclusions

Preoperative diaphragm dysfunction was associated with prolonged mechanical ventilation after lung transplantation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40560-022-00614-7.

Huashan perioperative nursing program for stroke patients undergoing contralateral seventh cervical nerve transfer

Background

A previous investigation regarding contralateral seventh cervical nerve transfer (CC7) revealed a novel and effective approach to improve arm function in patients with chronic spastic paralysis. The patients who underwent both CC7 and standard rehabilitation showed greater functional improvements and spasticity reductions than patients in the control group, who underwent rehabilitation only. Additional efforts are needed to maximize the benefits in patients and establishing a supporting nursing program is a promising method for achieving this goal.

Methods

The present Huashan nursing program was established in consideration of the following elements: providing routine perioperative care, ensuring surgical safety, and improving patient cooperation. Before surgery, psychiatric nursing, health education, and risk control were emphasized. After surgery, in addition to routine nursing and positioning, special attention was needed for targeted nursing in cases of postoperative adverse events. In addition, we performed descriptive statistical analysis of the clinical data of patients participating in the Huashan nursing program, focusing on postoperative adverse events. In total, 85 patients were included in the study, 10 of whom experienced adverse events, including severe pain (5, 5.88%), neck hematoma (2, 2.35%), dyspnea (2, 2.35%), and hoarseness (1, 1.18%). The above adverse events were alleviated through the targeted nursing care guided by the Huashan program.

Discussion

This article introduces the Huashan nursing program, which is based on preoperative evaluations, educational sessions, postoperative monitoring, and targeted nursing, for patients undergoing CC7. This nursing program helped promote and provided the opportunity to maximize the benefits of CC7.

Type 2 respiratory failure secondary to left hemidiaphragmatic paralysis

A 73-year-old man presented to the emergency department with worsening orthopnoea and exertional dyspnoea. He denied any other cardiorespiratory symptoms. The patient had a body mass index (BMI) of 23.3 kg·m⁻² (height 163 cm, weight 62 kg). Lung function tests 3 months before admission showed a ratio of forced expiratory volume in 1 s (FEV₁) to forced vital capacity (FVC) of 88%. He had a past medical history of hypothyroidism, for which he was on levothyroxine 50 μg daily, and type 2 diabetes mellitus, for which he was on metformin 500 mg twice daily. Past surgical history included a gastrectomy 3 years prior to admission performed for gastric cancer, which was subsequently complicated by a subphrenic abscess, pancreatitis and residual pancreatic insufficiency. The patient was a lifelong non-smoker, worked in construction, reared birds as a hobby, and lived in an urban area. He was not on any other medication.

This case describes an uncommon presentation of type 2 respiratory failure secondary to left hemidiaphragmatic paralysis. Emphasis is on the multitude of possible causes of hemidiaphragmatic paralysis and how to manage such a presentation.https://bit.ly/3Mcd2XI

Diaphragmatic weakness after transcatheter arterial chemoembolization of the right inferior phrenic artery for treatment of hepatocellular carcinoma: a comparison of outcomes after N-butyl cyanoacrylate versus gelatin sponge embolization

BACKGROUND

The inferior phrenic artery (IPA) is the most common extrahepatic feeder for hepatocellular carcinoma (HCC) during transhepatic arterial chemoembolization (TACE).

PURPOSE

To compare the incidence of diaphragmatic weakness in patients with HCC after TACE of the right IPA conducted using either N-butyl cyanoacrylate (NBCA) or gelatin sponge particles.

MATERIAL AND METHODS

Medical records of 111 patients who underwent TACE of the right IPA using NBCA were retrospectively reviewed and compared with data from 135 patients with IPA embolization using gelatin sponge particles.

RESULTS

The incidence of diaphragmatic weakness after the initial TACE procedure did not significantly differ between the groups (NBCA group 16.2%; gelatin sponge group 20.7%; P = 0.458). Five patients in the NBCA group and 11 in the gelatin sponge group showed spontaneous resolution of diaphragmatic weakness after a mean period of 3.5 months. Diaphragmatic weakness developed after the initial follow-up visit in 17 patients from the gelatin sponge group due to repeated TACE of the right IPA (mean 2.4 sessions; range 2-4 sessions), while it spontaneously developed without additional TACE procedures in one patient from the NBCA group. Permanent diaphragmatic weakness was less common in the NBCA than in the gelatin sponge group (12.6% and 25.2%, respectively; P = 0.017). The complete response rate did not significantly differ between the groups (NBCA group 16.2%; gelatin sponge group 25.9%; P = 0.065).

CONCLUSION

Use of NBCA rather than gelatin sponge particles for TACE of the right IPA resulted in a lower incidence of permanent diaphragmatic weakness.

Phrenic Nerve Palsy Following Radiation Therapy for Patient With Breast Cancer

INTRODUCTION

Breast cancer is the most common malignancy affecting women in US today. Radiotherapy used after breast-conserving surgery has been shown to decrease local recurrence while minimizing side effects. Peripheral neuropathy remains a common and well-known complication of radiotherapy for breast cancer; however, it is rarely associated with phrenic nerve palsy after treatment of breast cancer.

CASE PRESENTATION

We describe a 66-year-old woman with a significant past medical history of chronic obstructive pulmonary disease and asthma who presented with hypoxia after completing radiotherapy for breast cancer. After ruling out other causes of hypoxemia, the patient was diagnosed with diaphragmatic dysfunction, likely caused by phrenic nerve palsy resulting from radiotherapy-induced neuropathy after treatment of breast cancer.

CONCLUSION

This case is the first reported incidence of phrenic nerve palsy resulting from radiotherapy for breast cancer.

The Feasibility of Ultrasonographic Diaphragmatic Excursion in Healthy Dogs: Effect of Positioning, Diaphragmatic Location, and Body Weight of Dogs

Diaphragmatic excursion (DE) has been utilized for detecting respiratory related problems in humans. However, several factors should be considered such as the ultrasound technique and factors intrinsic to patients. Nevertheless, knowledge of the effect of these factors on DE in dogs is still lacking. The aim of this study was to evaluate the proper ultrasound technique by varying postures and diaphragmatic locations for DE measurement and to explore intrinsic factors such as diaphragmatic sides, sex, and body weight of dogs on DE. The prospective, analytic, cross-sectional study included 44 healthy dogs; 12 beagles and 32 dogs of other breeds. The experiment was divided into (i) an exploration of the proper ultrasound technique by varying postures (supine, standing, and recumbent in each of the right and left lateral positions), diaphragmatic locations (middle crus and proximal to the last rib), and diaphragmatic sublocations (xiphoid, mid, and proximal rib) for detection of DE and (ii) the evaluation of canine intrinsic factors affecting DE. The results show that the mid-diaphragmatic sublocation in the middle crus area in almost all positions revealed the highest percentage DE detection. However, DEs were revealed to be more accessible in the supine position. There was no significant difference in DE between the right and the left diaphragms or between the sexes of beagle dogs. However, body weight was significantly correlated with the DE among dogs of various sizes. In conclusion, the posture of the dogs and the diaphragmatic location can affect DE evaluation. Neither sex nor diaphragmatic side had an influence, but body weight was revealed as a major factor in DE in dogs.

Unilateral Diaphragmatic Paralysis in a Patient With COVID-19 Pneumonia

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is best known for causing febrile pneumonia with lung parenchymal involvement. However, that is often not the only disease presentation, as many studies have shown that coronavirus disease 2019 (COVID-19) can present with other complications involving the cardiovascular and neurologic systems. Here, we report a case of COVID-19 pneumonia presenting with a peculiar finding of unilateral diaphragmatic paralysis. The patient presented with dyspnea requiring oxygen support via a nasal cannula. He was managed with the hospital's COVID-19 treatment protocols and clinically improved within 14 days of admission. This case helps shine some light on the neuroinvasive potential of SARS-CoV-2.

A prospective evaluation of phrenic nerve injury after lung transplantation: Incidence, risk factors, and analysis of the surgical procedure

BACKGROUND

Phrenic nerve injury (PNI) is a complication of lung transplantation related to the surgical procedure and associated with increased morbidity. However, the incidence and risk factors, specifically regarding surgical techniques, have not been adequately studied.

METHODS

We conducted a prospective single-center study over 4-years, in recipients of lung transplantation with a normal pretransplant phrenic nerve conduction study (PNCS). Diaphragm ultrasound and PNCS were performed in the first 21 postoperative days and PNI was defined when both tests were abnormal. Patients were followed up until hospital discharge. The association between transplant characteristics and PNI was analyzed by using logistic regression models.

RESULTS

Two hundred eleven lung grafts implanted in 127 patients were included in the study. After lung transplantation, PNI was diagnosed in 43.3% of the subjects and 29% of the operated hemithorax. Regression logistic model showed that the variables related to PNI were female gender (p = 0.02), bilateral lung transplantation (BLT) (p = 0.001), right lung graft (p = 0.003), clamshell incision (p = 0.01), mediastinal adhesions (p = 0.002), longer operative time (p = 0.003), intraoperative extracorporeal support (p = 0.02), and blood transfusion (p = 0.003). Conversely, age >61 years (p = 0.008) and higher thoracic diameter (p = 0.04) were protective factors. The use of electrocautery, cardiac mechanical retractors, and diaphragmatic traction was not associated with PNI. Morbidity was increased without any difference in mortality.

CONCLUSIONS

PNI is a frequent complication after lung transplantation, associated with higher morbidity. Mainly risk factors were age, BLT, female gender, and variables related to surgical difficulties. Lung graft in the right hemithorax and mediastinal adhesiolysis were the most relevant technical variables.

Phrenic Nerve Reconstruction for Effective Surgical Treatment of Diaphragmatic Paralysis

ABSTRACT

Diaphragmatic paralysis due to phrenic nerve injury may cause orthopnea, exertional dyspnea, and sleep-disordered breathing. Phrenic nerve reconstruction may relieve symptoms and improve respiratory function. A retrospective review of 400 consecutive patients undergoing phrenic nerve reconstruction for diaphragmatic paralysis at 2 tertiary treatment centers was performed between 2007 and 2019. Symptomatic patients were identified, and the diagnosis was confirmed on radiographic evaluations. Assessment parameters included pulmonary spirometry (forced expiratory volume in 1 second and FVC), maximal inspiratory pressure, compound muscle action potentials, diaphragm thickness, chest fluoroscopy, and Short Form 36 Health Survey Questionnaire (SF-36) survey. There were 81 females and 319 males with an average age of 54 years (range, 19-79 years). The mean duration from diagnosis to surgery was 29 months (range, 1-320 months). The most common etiologies were acute or chronic injury (29%), interscalene nerve block (17%), and cardiothoracic surgery (15%). The mean improvements in forced expiratory volume in 1 second and FVC at 1 year were 10% (P < 0.01) and 8% (P < 0.05), respectively. At 2-year follow-up, the corresponding values were 22% (P < 0.05) and 18% (P < 0.05), respectively. Improvement on chest fluoroscopy was demonstrated in 63% and 71% of patients at 1 and 2-year follow-up, respectively. There was a 20% (P < 0.01) improvement in maximal inspiratory pressure, and compound muscle action potentials increased by 82% (P < 0.001). Diaphragm thickness demonstrated a 27% (P < 0.01) increase, and SF-36 revealed a 59% (P < 0.001) improvement in physical functioning. Symptomatic diaphragmatic paralysis should be considered for surgical treatment. Phrenic nerve reconstruction can achieve symptomatic relief and improve respiratory function. Increasing spirometry and improvements on Sniff from 1 to 2 years support incremental recovery with longer follow-up.

Diaphragm dysfunction: A comprehensive review from diagnosis to management

Although the diaphragm represents a critical component of the respiratory pump, the clinical presentations of diaphragm dysfunction are often non-specific and can be mistaken for other more common causes of dyspnoea. While acute bilateral diaphragm dysfunction typically presents dramatically, progressive diaphragm dysfunction associated with neuromuscular disorders and unilateral hemidiaphragm dysfunction may be identified incidentally or by recognising subtle associated symptoms. Diaphragm dysfunction should be considered in individuals with unexplained dyspnoea, restrictive respiratory function tests or abnormal diaphragm position on plain chest imaging. A higher index of suspicion should occur for individuals with profound orthopnoea, those who have undergone procedures in proximity to the phrenic nerve(s) or those with co-morbid conditions that are associated with diaphragm dysfunction, particularly neuromuscular disorders. A systematic approach to the evaluation of diaphragm function using non-invasive diagnostic techniques such as respiratory function testing and diaphragm imaging can often confirm a diagnosis. Neurophysiological assessment may confirm diaphragm dysfunction and assist in identifying an underlying cause. Identifying those with or at risk of respiratory failure can allow institution of respiratory support, while specific cases may also benefit from surgical plication or phrenic nerve pacing techniques. This article is protected by copyright. All rights reserved.

Noninvasive ventilation: An important option in the management of hemidiaphragm paralysis

Hemidiaphragm paralysis (HP) is a potential complication of cardiac surgery. While most patients are either asymptomatic or have mild symptoms, some are at risk of developing life-threatening hypercapnia. We present a case of a patient who developed HP after tricuspid valve replacement. Diaphragm plication was deferred due to underlying comorbidities, but over time she developed severe hypercapnic respiratory failure requiring intensive care unit admission. Chronic noninvasive ventilation therapy (NIV) was initiated, which improved her symptoms and hypercapnia and prevented further hospitalizations. For patients with iatrogenic HP unable to undergo diaphragm plication, Pulmonology referral for initiation of NIV should be strongly considered.

Unilateral diaphragm paralysis with COVID-19 infection

Neurological complications are well described in SARS-CoV-2, but for the first time we report a case of unilateral diaphragm paralysis occurring early in mechanical ventilation for respiratory failure due to such an infection. The patient subsequently required tracheostomy and ventilator support for 37 days, and had increased breathlessness and an elevated diaphragm at clinic review 9 months later. Dynamic chest radiography demonstrated persistent diaphragm paralysis with an accompanying postural change in lung volumes, and he subsequently underwent surgical plication. This case demonstrates that although persistent dyspnoea is a common feature following SARS-CoV-2 infection and is usually due to deconditioning or persistent parenchymal involvement, it can be due to other causes and needs to be investigated appropriately.

Minimally Invasive Plication of the Diaphragm: A Single-Center Prospective Study

OBJECTIVE

Plication of the diaphragm is a life-changing procedure for patients affected by diaphragm paralysis. Traditionally, this procedure is performed through a thoracotomy. Access to the diaphragm via this incision is poor and the indications for surgery are limited to patients who can actually sustain such an invasive approach and associated morbidities. A minimally invasive approach was developed to improve the surgical management of diaphragm paralysis.

METHODS

Patients underwent minimally invasive diaphragm plication either by video-assisted or robotic surgery through a 3-port technique with CO₂ insufflation. Patients were followed at the routine 6-week clinic and also by telephone consultation 6 to 12 months postoperatively. Data were collected on postoperative complications, postoperative pain or numbness, symptomatic improvement, and change to quality of life following surgery.

RESULTS

Forty-eight patients underwent 49 minimally invasive diaphragm plication. Median postoperative length of hospital stay was 4 days (range: 2 to 34 days) and there were no cases of mortality. Mean reduction in Medical Research Council dyspnea score per patient was 2.2 points (mode: 3 points). Twenty-eight patients (77.8%) reported a significant symptomatic improvement enabling improvements in quality of life, and 97.2% (n = 35) were satisfied with the surgical outcome.

CONCLUSIONS

Minimally invasive diaphragm plication is a safe procedure associated with prompt postoperative recovery. It is effective at reducing debilitating dyspnea and improving quality of life.

A 65-Year-Old Woman With Dyspnea After Atrial Fibrillation Ablation

CASE PRESENTATION

A 65-year-old woman with a history of chronic persistent atrial fibrillation, tobacco use, and COPD was admitted to the hospital 2 months after catheter ablation for persistent atrial fibrillation and dyspnea. Her dyspnea was present at rest and worsened by exertion with limitation to ambulating less than two blocks. She also endorsed a 1-month history of cough with minimally productive whitish sputum with frequent nocturnal exacerbations and orthopnea. She denied any fevers, chest pain, or hemoptysis.

Treatment for bilateral diaphragmatic dysfunction using phrenic nerve reconstruction and diaphragm pacemakers

OBJECTIVES

Bilateral diaphragmatic dysfunction results in severe dyspnoea, usually requiring oxygen therapy and nocturnal ventilatory support. Although treatment options are limited, phrenic nerve reconstruction (PR) offers the opportunity to restore functional activity. This study aims to evaluate combination treatment with PR and placement of a diaphragm pacemaker (DP) compared to DP placement alone in patients with bilateral diaphragmatic dysfunction.

METHODS

Patients with bilateral diaphragmatic dysfunction were prospectively enrolled in the following treatment algorithm: Unilateral PR was performed on the more severely impacted side with bilateral DP implantation. Motor amplitudes, ultrasound measurements of diaphragm thickness, maximal inspiratory pressure, forced expiratory volume, forced vital capacity and subjective patient-reported outcomes were obtained for retrospective analysis following completion of the prospective database.

RESULTS

Fourteen male patients with bilateral diaphragmatic dysfunction confirmed on chest fluoroscopy and electrodiagnostic testing were included. All 14 patients required nocturnal ventilator support, and 8/14 (57.1%) were oxygen-dependent. All patients reported subjective improvement, and all 8 oxygen-dependent patients were able to discontinue oxygen therapy following treatment. Improvements in maximal inspiratory pressure, forced vital capacity and forced expiratory volume were 68%, 47% and 53%, respectively. There was an average improvement of 180% in motor amplitude and a 50% increase in muscle thickness. Comparison of motor amplitude changes revealed significantly greater functional recovery on the PR + DP side.

CONCLUSIONS

PR and simultaneous implantation of a DP may restore functional activity and alleviate symptoms in patients with bilateral diaphragmatic dysfunction. PR plus diaphragm pacing appear to result in greater functional muscle recovery than pacing alone.

A Novel Normalized Cross-Correlation Speckle-Tracking Ultrasound Algorithm for the Evaluation of Diaphragm Deformation

Objectives: To develop a two-dimensional normalized cross-correlation (NCC)-based ultrasonic speckle-tracking algorithm for right diaphragm deformation analysis.

Methods: Six healthy and eight mechanical ventilation patients were enrolled in this study. Images were acquired by a portable ultrasound system in three sections. DICOM data were processed with NCC to obtain the interframe/cumulative vertical and horizontal displacements, as well as the global strain of the right diaphragm, with continuous tracking and drift correction.

Results: The NCC algorithm can track the contraction and relaxation of the right diaphragm by following the respiratory movement continuously. For all three sections, the interframe and accumulated horizontal displacements were both significantly larger than the corresponding vertical displacements (interframe p values: 0.031, 0.004, and 0.000; cumulative p values: 0.039, 0.001, and <0.0001). For the global strain of the right diaphragm, there was no significant difference between each pair of sections (all p > 0.05), regardless of whether the horizontal interval of the initial diaphragm point was 1, 3, 5, or 10 times in the sampling interval.

Conclusions: This study developed a novel diaphragm deformation ultrasound imaging method. This method can be used to estimate the diaphragm interframe/accumulated displacement in the horizontal and vertical directions and the global strain on three different imaging planes, and it was found that the strain was not sensitive to the imaging plane.

Hemidiaphragmatic Paralysis Post Stroke Leading to Hypercapneic Respiratory Failure

Unilateral diaphragmatic paralysis is a rare complication after stroke. We report a case of right-sided hemidiaphragmatic paralysis after stroke in a 51-year-old man who presented with shortness of breath and orthopnea. Chest X-ray (CXR) revealed an elevated right-sided hemidiaphragm. The weakened diaphragmatic contraction from paralyzed right hemidiaphragm resulted in persistent atelectasis of the right lung base and inadequate alveolar ventilation leading to the development of right basal pneumonia with hypercapneic respiratory failure. However, the patient had a remarkable improvement with the appropriate institution of non-invasive ventilation and medical management with intravenous antibiotics.

Chronic respiratory dysfunction due to diaphragmatic paralysis following penetrating neck trauma: A case report

RATIONALE

Respiratory dysfunction resulting from unilateral diaphragmatic paralysis during neck trauma is very rare in adults. We describe the symptoms, diagnosis and treatment of 1 patient with chronic respiratory insufficiency, in whom the diaphragmatic paralysis was associated with phrenic nerve injury due to penetrating neck trauma.

PATIENT CONCERNS

A 50-year-old worker was admitted because of left penetrating neck trauma. Imaging investigations demonstrated elevation of the left hemidiaphragm and the C5 and C6 roots avulsion. He complained of gradually worsening dyspnea on exertion 2 months later.

DIAGNOSES

The patient was diagnosed with chronic respiratory dysfunction secondary to diaphragmatic paralysis, which caused by phrenic nerve injury.

INTERVENTIONS

A conventional video-assisted thoracoscopic diaphragm plication was performed after failed conservative management.

OUTCOMES

The respiratory status improved markedly, and he did well without recurrence until 2 years' follow-up.

LESSONS

The possibilities of phrenic nerve palsy and diaphragmatic paralysis should not be overlooked during the evaluation of neck trauma.

A Rare Case of Amyotrophic Lateral Sclerosis With Asymmetrical Phrenic Nerve Lesion Presenting With Acute Respiratory Failure as an Initial Manifestation

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that causes muscle weakness, disability, and eventually, death. Respiratory failure is the leading cause of death in ALS. It is common in the advanced stages of the disease. However, acute respiratory failure is a presenting symptom in only a small number of patients, such as in our case. Here, we present the case of a 54-year-old woman with ALS presenting with respiratory failure due to unilateral diaphragm paralysis as the first manifestation. Although rare, respiratory muscle function failure can be the first symptom of motor neuron disease. Therefore, a motor neuron disease such as ALS, which leads to respiratory muscle weakness and diaphragm paralysis, should be considered in cases of unexplained acute respiratory failure.

Phrenic nerve conduction study to diagnose unilateral diaphragmatic paralysis

BACKGROUND

Unilateral diaphragmatic paralysis (UDP) has major clinical and etiological implications and, therefore, is important to diagnose. Lung function tests and invasive transdiaphragmatic pressure (Pdi) measurements are widely used to this end but, contrary to phrenic nerve conduction study (NCS), they require volitional maneuvers and/or may be poorly tolerated by patients. The purpose of this study was to compare the diagnostic accuracy of Pdi and phrenic NCS for UDP.

METHODS

We retrospectively reviewed 28 patients with suspected UDP. The diagnosis established during a multidisciplinary meeting was the reference standard.

RESULTS

Phrenic NCS correlated well with Pdi (r = 0.82, P < .005), and the two tests showed good agreement (κ = 0.82, P < .005). Phrenic NCS and Pdi measurements both had 95% sensitivity, 87.5% specificity, 95% positive predictive, and 87.5% negative predictive values.

CONCLUSIONS

Both tests were highly sensitive and specific. Phrenic NCS measurement is a simple, reproducible, noninvasive method whose results correlate well with Pdi and provide insight into the UDP mechanism. In the most difficult cases, combining lung function tests, respiratory muscle assessments, and phrenic NCS can help to establish the diagnosis.

Assessing the impact of posture on diaphragm morphology and function using an open upright MRI system-A pilot study

PURPOSE

The diaphragm is the most important muscle of respiration. Disorders of the diaphragm can have a deleterious impact on respiratory function. We aimed to evaluate the use of an open-configuration upright low-field MRI system to assess diaphragm morphology and function in patients with bilateral diaphragm weakness (BDW) and chronic obstructive pulmonary disease (COPD) with hyperinflation.

METHOD

The study was approved by the National Research Ethics Committee, and written consent was obtained. We recruited 20 healthy adult volunteers, six subjects with BDW, and five subjects with COPD with hyperinflation. We measured their vital capacity in the upright and supine position, after which they were scanned on the 0.5 T MRI system during 10-s breath-holds at end-expiration and end-inspiration in both positions. We developed and applied image analysis methods to measure the volume under the dome, maximum excursion of hemidiaphragms, and anterior-posterior and left-right extension of the diaphragm.

RESULTS

All participants were able to complete the scanning protocol. The patients found scanning in the upright position more comfortable than the supine position. All differences in the supine inspiratory-expiratory parameters, excluding left-right extension, were significantly smaller in the BDW and COPD groups compared with healthy volunteers. No significant correlation was found between the postural change in diaphragm morphology and vital capacity in either group.

CONCLUSION

Our combined upright-supine MR imaging approach facilitates the assessment of the impact of posture on diaphragm morphology and function in patients with BDW and those with COPD with hyperinflation.

Respiratory Failure Secondary to Diaphragmatic Paralysis from Acute Exacerbation of Dermatomyositis

Dermatomyositis (DM) is an idiopathic inflammatory disorder that presents with proximal muscle weakness and typical DM skin changes. DM can involve other organs such as the lung, esophagus, and heart. Diaphragmatic muscle paralysis is an unrecognized clinical presentation of acute DM exacerbation. A 58-year-old man with a history of DM presented to the hospital after sustaining a cardiorespiratory arrest. Before arrest, he had been suffering from progressive dyspnea and muscle weakness. Immunosuppressive therapy of tacrolimus for DM was recently discontinued due to renal toxicity. Bedside ultrasound of the diaphragm while intubated revealed evidence of bilateral diaphragmatic paralysis. After extubation, supine and upright pulmonary function tests (PFT) and sniff test results strengthened the diagnosis of diaphragmatic paralysis. The patient was worked up for an acute DM exacerbation as the likely etiology of the severe diaphragmatic muscle weakness (diaphragmatic paralysis) and ventilatory failure. Skin and muscle biopsy confirmed the diagnosis of active DM. The patient was treated with high dose steroids and mycophenolate mofetil, following which he soon recovered.

Contemporary analysis of phrenic nerve injuries following cryoballoon-based pulmonary vein isolation: A single-centre experience with the systematic use of compound motor action potential monitoring

BACKGROUND

Phrenic nerve injury (PNI) remains one of the most frequent complications during cryoballoon-based pulmonary vein isolation (CB-PVI). Since its introduction in 2013, the use of compound motor action potential (CMAP) for the prevention of PNI during CB-PVI is increasing; however, systematic outcome data are sparse.

METHODS

The CMAP technique was applied in conjunction with abdominal palpation during pacing manoeuvres (10 mV, 2 ms) from the superior vena cava for 388 consecutive patients undergoing CB-PVI between January 2015 and May 2017 at our tertiary arrhythmia centre. Cryoablation was immediately terminated when CMAP amplitude was reduced by 30%.

RESULTS

Reductions in CMAP amplitude were observed in 16 (4%) of 388 patients during isolation of the right veins. Of these, 11 (69%) patients did not manifest a reduction in diaphragmatic excursions. The drop in CMAP amplitude was observed in 10 (63%) patients during ablation of the right superior pulmonary veins (PVs) and in 7 (44%) patients during ablation of the right inferior PVs. Postprocedural persistent PNI was observed in three of four patients for a duration of 6 months, with one of these patients remaining symptomatic at the 24-month follow-up. One of the four patients was lost to long-term follow-up.

CONCLUSIONS

All PNIs occurred during right-sided CB-PVI and were preceded by a reduction in CMAP amplitude. Thus, the standardized use of CMAP surveillance during CB-PVI is easily applicable, reliable and compared with other studies, results in a lower number of PNIs.

Diaphragm paralysis: a case report

INTRODUCTION

Bilateral paralysis of the diaphragm may be an idiopathic clinical condition or associated with several diseases such as trauma, surgery, viral infections, neurologic disorders. The diaphragm is the main respiratory muscle. It is a cupoliform muscle-tendon structure, innervated bilaterally by phrenic nerve, which originates from C3-C5 nerve roots. Diaphragmatic paralysis is a clinical disorder that generates hypoventilation and basal pulmonary atelectasis, predisposing to hypercapnic respiratory failure. The clinic manifestations mimic cardio-respiratory pathologies, therefore often misdiagnosticated.

CASE PRESENTATION

A 55-year-old man with a previous C6-7 traumatic fracture, referred multiple accesses to the emergency room for acute nocturnal dyspnoea, treated with antibiotic therapy, diuretic therapy and long-term oxygen therapy, without beneficial effects. He referred to our pulmonary clinic for evaluation of persistent and worsening orthopnoea due to unknown cause for about 2 years. Clinical examination, respiratory functional tests and diaphragm ultrasound revealed a strong suspicion of diaphragmatic deficit, confirmed by electromyography.

CONCLUSIONS

The patient accesses to the emergency room numerous times and the clinical frame have been always oriented towards a cardio-respiratory origin. From the onset of the symptom to the respiratory evaluation, about 2.5 years have passed. The manifestation of clear orthopnoea has addressed the functional respiratory study towards a more thorough diaphragmatic evaluation assessed by ultrasound.

Diaphragmatic paralysis: Evaluation in infants with congenital Zika syndrome

BACKGROUND

Paralysis of the diaphragm in newborn infants can lead to recurrent infections and life-threatening respiratory insufficiency. The clinical diagnosis of unilateral diaphragmatic paralysis has been reported in infants with laboratory evidence of congenital Zika virus infection and/or the congenital Zika syndrome (CZS) phenotype but no evaluation of phrenic nerve function has been described. All reported infants have had accompanying arthrogryposis. High infant mortality is reported.

METHODS

The causal mechanism of congenital diaphragmatic paralysis was evaluated in three infants with arthrogryposis as a manifestation of CZS (two of the three infants had laboratory evidence of ZIKV infection shortly after birth; the remaining infant had negative serology for ZIKV when first tested at 7 months of age). Electromyography and phrenic nerve compound muscle action potential (CMAP) were performed in all infants with diaphragmatic paralysis demonstrated on imaging studies.

RESULTS

All infants had evidence of moderate chronic involvement of peripheral motor neurons. Phrenic nerve CMAP was reduced on the side of the diaphragmatic paralysis in two infants and reduced bilaterally in the remaining infant who had primarily anterior involvement of the diaphragm. All three infants had multiple medical complications and one infant died at 18 months of age.

CONCLUSION

Evaluation of three infants with CZS and diaphragmatic paralysis demonstrated phrenic nerve dysfunction. In these and other affected infants, arthrogryposis appears to be a constant co-occurring condition and health problems are significant; both conditions are likely due to involvement of the peripheral nervous system in some infants with CZS.

Unilateral loss of thoracic motion after blunt trauma: a sign of acute Brown-Séquard syndrome

Late-onset Brown-Séquard syndrome (BSS) is a rare condition resulting from a spinal cord injury that develops weeks to years after a blunt trauma. Acute-onset BSS after a blunt injury has been rarely reported. Here, we report on a case of BSS, in a 58-year-old man, that developed immediately after a motor vehicle accident. Upon admission, loss of right thoracic motion, complete right paresis, and loss of pain and temperature sensations below the C3 level on the left side were observed. Magnetic resonance imaging showed hyperintensities within the cervical spinal cord at the C2–C3 level, confirming the diagnosis of BSS. Thoracic motion rapidly recovered, but other neurological sequelae persisted. BSS related to cervical cord injury should be suspected when patients develop hemiparesis and contralateral sensory loss immediately after a blunt trauma. Likewise, clinicians should be aware that unilateral loss of thoracic motion could be an important sign of BSS.