In a porcine model of implantable pacemakers for pediatric unilateral diaphragm paralysis, the phrenic nerve is the best target.

BACKGROUND: A frequent complication of Fontan operations is unilateral diaphragmatic paresis, which leads to hemodynamic deterioration of the Fontan circulation. A potential new therapeutic option is the unilateral diaphragmatic pacemaker. In this study, we investigated the most effective stimulation location for a potential fully implantable system in a porcine model. METHODS: Five pigs (20.8 ± 0.95 kg) underwent implantation of a customized cuff electrode placed around the right phrenic nerve. A bipolar myocardial pacing electrode was sutured adjacent to the motor point and peripherally at the costophrenic angle (peripheral diaphragmatic muscle). The electrodes were stimulated 30 times per minute with a pulse duration of 200 µs and a stimulation time of 300 ms. Current intensity was the only variable changed during the experiment. RESULTS: Effective stimulation occurred at 0.26 ± 0.024 mA at the phrenic nerve and 7 ± 1.22 mA at the motor point, a significant difference in amperage (p = 0.005). Even with a maximum stimulation of 10 mA at the peripheral diaphragm muscle, however, no effective stimulation was observed. CONCLUSION: The phrenic nerve seems to be the best location for direct stimulation by a unilateral thoracic diaphragm pacemaker in terms of the required amperage level in a porcine model.

Non-invasive diagnosis of diaphragmatic paralysis in botulism using ultrasound.

This case study explores foodborne botulism, a severe illness caused by botulinum neurotoxin-contaminated food. It leads to bilateral descending paralysis, involving the diaphragm. We highlight diaphragmatic ultrasound as a non-invasive diagnostic tool. A 50-year-old obese male developed diplopia and weakness after consuming contaminated food, rapidly progressing to severe symptoms. Mechanical ventilation became necessary due to respiratory failure. Diaphragmatic ultrasound confirmed bilateral diaphragm paralysis despite early antitoxin treatment. The patient experienced complications, requiring tracheostomy and rehabilitation. After five months, he fully recovered diaphragmatic function. This study underscores botulism's life-threatening nature and the vital role of supportive care. Diaphragmatic ultrasound is a safe and effective method for assessing diaphragmatic function in such cases, obviating ionizing radiation exposure. We recommend its routine use for evaluating botulism-induced paralysis.

Orthopnea secondary to brachial plexitis with bilateral diaphragmatic paralysis.

BACKGROUND: Diaphragmatic paralysis can present with orthopnea. We report a unique presentation of bilateral diaphragmatic paralysis, an uncommon diagnosis secondary to an unusual cause, brachial plexitis. This report thoroughly describes the patient's presentation, workup, management, and outcome. It also reviews the literature on diaphragmatic paralysis and Parsonage-Turner syndrome. CASE PRESENTATION: A 50-year-old male patient developed insidious orthopnea associated with left shoulder and neck pain over three months with no associated symptoms. On examination, marked dyspnea was observed when the patient was asked to lie down; breath sounds were present and symmetrical, and the neurological examination was normal. The chest radiograph showed an elevated right hemidiaphragm. Echocardiogram was normal. There was a 63% positional reduction in Forced Vital Capacity and maximal inspiratory and expiratory pressures on pulmonary function testing. The electromyogram was consistent with neuromuscular weakness involving both brachial plexus and diaphragmatic muscle (Parsonage and Turner syndrome). CONCLUSIONS: Compared to unilateral, bilateral diaphragmatic paralysis may be more challenging to diagnose. On PFT, reduced maximal respiratory pressures, especially the maximal inspiratory pressure, are suggestive. Parsonage-Turner syndrome is rare, usually with unilateral diaphragmatic paralysis, but bilateral cases have been reported.

Early-Onset Respiratory Muscle Paralysis in Crotalic Envenomation: A Case Study.

Crotalic envenomation is responsible for approximately 8%-13% of ophidism cases in Brazil, yet it is associated with the highest mortality among snakes. We describe the case of a patient bitten by a rattlesnake who developed ventilatory muscle paralysis within hours after envenomation. While diaphragmatic paralysis is a rare late neurotoxic event following crotalic envenomation, in this case, paralysis occurred early but was rapidly reversed after antivenom administration. This report discusses potential contributing factors based on a comprehensive literature review.

Validación de la ecografía Point-of-Care para el diagnóstico de hernia diafragmática: a propósito de un caso / Validation of Point-of-Care ultrasound in the diagnosis of a diaphragmatic hernia

La ecografía Point-of-Care (POCUS) es una herramienta sensible y específica para diagnosticar de manera precoz la patología del diafragma en pacientes críticos. Presentamos un caso clínico de un paciente con antecedentes de hernia diafragmática iatrogénica que ingresó en la unidad de reanimación tras una laparotomía exploradora de emergencia. Aprovechando el diagnóstico conocido de hernia diafragmática, describimos los signos clínicos que debemos encontrar en la evaluación POCUS para establecer el diagnóstico de hernia diafragmática: 1)fracción de acortamiento diafragmático normal bilateral; 2)excursión diafragmática reducida, y 3)posición cefálica de la cúpula diafragmática 4)mayor en supino que en sedestación. Igualmente, proponemos una sistemática de exploración ecográfica del diafragma y una clasificación diferencial de la disfunción diafragmática evaluada mediante POCUS en función de la correcta integridad y el buen funcionamiento del músculo periférico y del tendón central diafragmáticos en el paciente crítico.(AU)

Point-of-care ultrasound (POCUS) is a sensitive, specific tool for early diagnosis of diaphragm pathology in critically ill patients. We report the case of a patient with a history of iatrogenic diaphragmatic hernia who was admitted to the Resuscitation Unit after an emergency exploratory laparotomy. As the diagnosis of diaphragmatic hernia had already been confirmed, we determined the POCUS features that establish the diagnosis of diaphragmatic hernia: (1)normal bilateral diaphragmatic shortening fraction; (2)decreased diaphragmatic excursion, and (3)cephalic position of the diaphragmatic dome (4)greater in supine than in sitting position. We also outline a systematic ultrasound examination of the diaphragm and a POCUS-based differential classification of diaphragmatic dysfunction based on the functional integrity of the peripheral muscle and central diaphragmatic tendon in critically ill patients.(AU)

A porcine model of postoperative hemi-diaphragmatic paresis to evaluate a unilateral diaphragmatic pacemaker.

Unilateral phrenic nerve damage is a dreaded complication in congenital heart surgery. It has deleterious effects in neonates and children with uni-ventricular circulation. Diaphragmatic palsy, caused by phrenic nerve damage, impairs respiratory function, especially in new-borns, because their respiration depends on diaphragmatic contractions. Furthermore, Fontan patients with passive pulmonary perfusion are seriously affected by phrenic nerve injury, because diaphragmatic contraction augments pulmonary blood flow. Diaphragmatic plication is currently employed to ameliorate the negative effects of diaphragmatic palsy on pulmonary perfusion and respiratory mechanics. This procedure attenuates pulmonary compression by the abdominal contents. However, there is no contraction of the plicated diaphragm and consequently no contribution to the pulmonary blood flow. Hence, we developed a porcine model of unilateral diaphragmatic palsy in order to evaluate a diaphragmatic pacemaker. Our illustrated step-by-step description of the model generation enables others to replicate and use our model for future studies. Thereby, it might contribute to investigation and advancement of potential improvements for these patients.

Peri-operative Hemi-diaphragmatic Variations After Brachial Plexus Block Above the Clavicle: A Prospective Observational Study of the Contralateral Side.

OBJECTIVE: Hemi-diaphragm palsy after brachial plexus block above the clavicle (BPBAC) occurs frequently, but few patients develop post-operative pulmonary complications (PPC). We hypothesized that contralateral hemidiaphragm function increases after BPBAC. This contralateral function preserves global diaphragmatic function, avoiding PPC in the case of ipsilateral hemi-diaphragm palsy. METHODS: This prospective observational cohort study included 64 adult patients undergoing shoulder surgery with planned BPBAC (interscalene brachial plexus block and supraclavicular block). The Thickening Fraction (TF) was measured by ultrasound in both hemi-diaphragms, ipsilateral (TF ipsilateral) and contralateral (TFcontralateral) to the BPBAC, before and after the surgery. TFglobal is the sum of TFipsilateral and TFcontralateral. PPC were defined as occurrences of dyspnea, tachypnea, SpO2 <90% or SpO2/FiO2 <315. RESULTS: TFcontralateral increased significantly (an average of 40%) after BPBAC (p = 0.001), and TFipsilateral decreased (an average of 72%). After BPBAC, 86% of patients had a decreased TFipsilateral and 59% of patients an increased TFcontralateral at post-operatively. Only 17% of patients have PPC. CONCLUSION: After BPBAC, global diaphragm function decreases because of ipsilateral hemi-diaphragm reduction, but less than expected because of increased contralateral hemi-diaphragm function. As a part of diaphragm function, contralateral hemi-diaphragm function must be checked.

An Analysis of Respiratory Muscle Paralysis of Adult Patients in Guillain-Barré Syndrome: A Retrospective Analysis.

Respiratory muscle paralysis is known as a very common complication of Guillain-Barré syndrome (GBS). However, most research has focused on its later stages rather than its earlier stages, including the prognosis of patients with this condition, or factors that act as early predictors of risk. Therefore, our study aimed to identify early predictors of respiratory muscle paralysis in patients with GBS and determine the short-term prognosis of such patients. We recruited 455 GBS patients (age ≥ 18) who had been hospitalized in the First Affiliated Hospital of Harbin Medical University between 2016 and 2021, retrospectively. We recorded clinical and laboratory data and used linear and logistic regression analysis to investigate the relationship between early clinical, examination results, and subsequent respiratory muscle paralysis. Among the 455 patients, 129 were assigned to a respiratory muscle paralysis group and 326 were assigned to a non-respiratory muscle paralysis group. Compared with the non-affected group, the time from onset to admission was shorter (p = 0.0003), and the Medical Research Council (MRC) score at admission and discharge was smaller in the affected group (p < 0.0001). Compared with the non-affected group, the affected group had higher Hughes and Erasmus GBS Respiratory Insufficiency Score (EGRIS) scores at admission and longer hospital stays (p < 0.0001). Patients in the affected group were more likely to have bulbar palsy and lung infections (p < 0.0001). To conclude, bulbar palsy, a higher EGRIS score and Hughes score at admission, a lower MRC score, and a shorter time between onset and admission, are all predictive risk factors for respiratory muscle paralysis in patients with GBS. An increase in any of these factors increases the risk of muscle paralysis. Patients with respiratory muscle paralysis have a poorer short-term prognosis than those without respiratory muscle paralysis. Therefore, we should attempt to identify patients with one or more of these characteristics in the early stages of admission, provide ventilation management, and administer IMV treatment if necessary.

[Infraclavicular block for elbow surgery in a patient with pneumonectomy: Case report]. / Pnömonektomili bir hastada dirsek cerrahisi için infraklavikular blok uygulamasi: Olgu sunumu.

Diaphragmatic paralysis is one of the most important complications of upper extremity blocks and therefore limits the use of these blocks in patients with impaired respiratory functions. The appropriate block type should be selected by evaluating the location of the surgery and the risks of diaphragmatic paralysis of various blocks. In this case report, we aimed to evaluate the peripheral nerve blocks associated with diaphragmatic paralysis by presenting the anesthesia management of a patient with pneumonectomy planned for elbow arthroplasty due to elbow luxation.

Unilateral Diaphragmatic Paralysis After Stereotactic Ablative Radiation Therapy to a Lung Tumor Abutting the Course of the Phrenic Nerve.

We present the case of a woman with metastatic adenoid cystic carcinoma who received stereotactic ablative radiation therapy with a total dose of 50 Gy in 4 fractions to 2 lung metastases and developed symptomatic left phrenic nerve injury 2 years after radiation. The maximum dose to the approximate location of the phrenic nerve was 57.7 Gy, which corresponds to a biologically effective dose for late effects (using α/ß ratio = 3) of 335.14 Gy. Here, we discuss the case, planning considerations by radiation oncologists and medical physicists, and the multidisciplinary medical management of this patient.

Proof of concept of an accelerometer as a trigger for unilateral diaphragmatic pacing: a porcine model.

BACKGROUND: Unilateral diaphragmatic paralysis in patients with univentricular heart is a known complication after pediatric cardiac surgery. Because diaphragmatic excursion has a significant influence on perfusion of the pulmonary arteries and hemodynamics in these patients, unilateral loss of function leads to multiple complications. The current treatment of choice, diaphragmatic plication, does not lead to a full return of function. A unilateral diaphragmatic pacemaker has shown potential as a new treatment option. In this study, we investigated an accelerometer as a trigger for a unilateral diaphragm pacemaker (closed-loop system). METHODS: Seven pigs (mean weight 20.7 ± 2.25 kg) each were implanted with a customized accelerometer on the right diaphragmatic dome. Accelerometer recordings (mV) of the diaphragmatic excursion of the right diaphragm were compared with findings using established methods (fluoroscopy [mm]; ultrasound, M-mode [cm]). For detection of the amplitude of diaphragmatic excursions, the diaphragm was stimulated with increasing amperage by a cuff electrode implanted around the right phrenic nerve. RESULTS: Results with the different techniques for measuring diaphragmatic excursions showed correlations between accelerometer and fluoroscopy values (correlation coefficient 0.800, P < 0.001), accelerometer and ultrasound values (0.883, P < 0.001), and fluoroscopy and ultrasound values (0.816, P < 0.001). CONCLUSION: The accelerometer is a valid method for detecting diaphragmatic excursion and can be used as a trigger for a unilateral diaphragmatic pacemaker.

A comparison of short-term outcomes following robotic-assisted vs. open transthoracic diaphragm plication.

Diaphragm paralysis and eventration are rare conditions in adults. Symptomatic patients may benefit from surgical plication of the elevated hemidiaphragm. The objective of this study was to compare short-term outcomes and length of stay following robotic-assisted vs. open diaphragm plication. A multicenter retrospective study was conducted that identified patients undergoing unilateral hemidiaphragm plication from 5/2008 to 12/2020. The first RATS plication was performed in 11/2018. Electronic medical records were reviewed, and outcomes were compared between RATS and open approach. One hundred patients underwent diaphragm plication, including thirty-nine (39.0%) RATS and sixty-one (61.0%) open cases. Patients undergoing RATS diaphragm plication were older (64 years vs. 55 years, p = 0.01) and carried a higher burden of comorbidities (Charlson Comorbidity Index: 2.0 vs. 1.0, p = 0.02). The RATS group had longer median operative times (146 min vs. 99 min, p < 0.01), but shorter median hospital length of stays (3.0 days vs. 6.0 days, p < 0.01). There was a non-significant trend toward a decreased rate of 30-day postoperative complications (20.5% RATS vs. 32.8% open, p = 0.18) and 30-day unplanned readmissions (7.7% RATS vs. 9.8% open, p > 0.99). RATS is a technically feasible and safe option for performing diaphragm plications. This approach increases the surgical candidacy of older patients with a higher burden of comorbid disease without increasing complication rates, while reducing length of hospital stay.

Robotic diaphragm plication: functional and surgical outcomes of a single-center experience.

BACKGROUND: Diaphragm plication remains the only effective treatment for diaphragm paralysis. Robot-assisted thoracoscopic (RATS) diaphragm plication combines advantages of open and thoracoscopic techniques. We present our experiences focussing on lung-function improvement and surgical outcome. METHODS: In this single-center retrospective study with comparative analysis, perioperative data of all patients who underwent RATS or thoracoscopic (VATS) diaphragm plication between 2015 and 2022 at our institution were assessed. Functional outcome was analysed with pre- and postoperative pulmonary function tests in sitting and supine position. RESULTS: We included 43 diaphragm plications, of which 31 were performed via RATS. Morbidity in the RATS- and VATS-cohort were 13 and 8%, respectively (p = 0.64), without any major complication (Clavien-Dindo ≥ III, 0%). Surgical time for RATS diaphragm plication was reduced drastically with a median operating time for the first 16 patients of 136 min (range 84-185) and 84 min (range 56-122) for the most recent 15 patients (p < 0.0001). Pulmonary function testing after RATS-plication showed a mean increase in vital capacity (VC) of 9% (SD 8, p < 0.0001) and of 7% (SD 9, p = 0.0009) in forced expiratory volume in 1 s (FEV1) when sitting and 9% (SD 8, p < 0.0001) for VC as well as 10% (SD 8, p = 0.0001) for FEV1 when in supine position. CONCLUSION: RATS diaphragm plication is a very safe and feasible approach, yielding good results in improving patients' pulmonary function. Further studies are required to elucidate possible advantages over VATS or open approaches.