Hepatitis E and diaphragmatic dysfunction: Case series and review of the literature.

INTRODUCTION: The causes of diaphragmatic paresis are manifold. An association between neuralgic amyotrophy (NA) and hepatitis E virus (HEV) infection has been reported. We wondered about the prevalence of diaphragmatic disfunction and hepatitis E infection in our clinic. METHODS: From July 1st, 2020 to August 31st, 2023, patients presenting with diaphragmatic dysfunction and simultaneous clinical symptoms of an acute NA, or a history of NA, as well as patients with previously unexplained diaphragmatic dysfunction were examined for HEV infection. RESULTS: By August 31st, 2023, 13 patients with diaphragmatic dysfunction and HEV infection were diagnosed (4 women, 9 men). Mean age was 59 ± 10 years. Liver values were normal in all patients. The median latency to diagnosis was five months (range: 1-48 months); nine patients, 4 of them with typical symptoms of NA, presented with acute onset three patients showed bilateral diaphragmatic dysfunction. All patients had a positive IgG immunoblot. Seven patients, three with NA, had an elevated hepatitis E IgM titer and six of them also a positive IgM immunoblot. In all cases, O2C hepatitis genotype 3 was identified. In eight cases, all those with a high IgG titer >125, the O2 genotype 1 was also detected. CONCLUSION: NA that shows involvement of the phrenic nerve resulting in diaphragmatic dysfunction and dyspnoea, may be associated with HEV infection. The observation of 13 patients with diaphragmatic dysfunctions and HEV infection within a period of three years indicates a high number of undetected HEV-associated diaphragmatic dysfunction in the population, especially in the absence of NA symptoms. Therefore, even in diaphragmatic dysfunction without NA symptoms and causative damaging event, HEV infection should be considered, as it may represent a subform of NA with only phrenic nerve involvement. Therapy of HEV-associated diaphragmatic dysfunction in the acute phase is an open question. In view of the poor prognosis for recovery, antiviral therapy should be discussed. However, no relevant data are currently available.

[Quality of life in patients with postoperative unilateral diaphragm relaxation]. / Kachestvo zhizni patsientov s odnostoronnei relaksatsiei diafragmy posle khirurgicheskogo lecheniya.

OBJECTIVE: To evaluate the quality of life before and after video-assisted thoracoscopic plication of relaxed dome of diaphragm. MATERIAL AND METHODS: The study included 17 patients operated on for unilateral relaxation of diaphragm. We analyzed quality of life in preoperative period, 1, 3, 6 and 12 months after surgery using the SF-36 and EuroQ-5D-5L questionnaires. To assess the impact of abnormality on respiratory function, we estimated diaphragm position, spirometry data and SGRQ scores. RESULTS: FVC increased by 16.5% after 1 month, 19.5% after 6 months and 20.1% after 12 months. In addition, FEV1 significantly increased (by 12.6% after 1 month, 10.1% after 6 months and 12.7% after 12 months). Mean values of diaphragm elevation in postoperative period decreased by 25.5-25.6%. According to the SF-36 and EuroQ-5D-5L questionnaires, physical and psychological health components significantly increased within a month after surgical treatment. According to the SGRQ questionnaire, influence of disease on overall status decreased a month after surgery as evidences by lower total score (p<0.05). CONCLUSION: Objective and survey data revealed significant improvement in quality of life after surgery. A trend towards higher quality of life was demonstrated by all questionnaires in a month after surgery.

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.

Botox injection into the lower esophageal sphincter induces hiatal paralysis and gastroesophageal reflux.

BACKGROUND: Endoscopic intrasphincteric injection of Botox (ISIB) is used routinely for the treatment of achalasia esophagus and other spastic motor disorders. Studies show that the ISIB reduces the smooth muscle lower esophageal sphincter (LES) pressure. The esophageal hiatus, formed by the right crus of diaphragm, surrounds the cranial half of the LES and works like an external LES. We studied the effects of ISIB on the LES and hiatal contraction and gastroesophageal reflux (GER). Fourteen patients treated with ISIB were studied. Esophageal manometry-impedance recordings were performed before and after the ISIB. Hiatal contraction was assessed during tidal inspiration, forced inspiration, Müller's maneuver, and straight leg raise. In 6 subjects, the manometry were repeated 6-12 mo after the ISIB. The esophagogastric junction (EGJ) pressure was measured at end expiration (LES pressure) and at the peak of maneuvers (hiatal contraction). Transdiaphragmatic pressure (pdi; force of diaphragmatic contraction) was measured at the peak of forced inspiration. GER was measured from the impedance recordings. The EGJ pressure at end expiration (LES pressure) decreased significantly after the Botox injection. The peak EGJ pressure at tidal inspiration, forced inspiration, Müller's maneuver, and straight leg raise was also dramatically reduced by the ISIB. There was no effect of Botox on the pdi during forced inspiration. Seven of 10 subjects demonstrated GER during maneuvers following the ISIB. Six to 12 mo after ISIB, the LES and hiatal contraction pressure returned to the pre-ISIB levels. ISIB, in addition to decreasing LES pressure, paralyzes the esophageal hiatus (crural diaphragm) and induces GER.NEW & NOTEWORTHY The sphincter mechanism at the lower end of the esophagus comprises smooth muscle lower esophageal sphincter (LES) and skeletal muscle crural diaphragm (hiatus). Current thinking is that the endoscopic intrasphincteric injection of Botox (ISIB), used routinely for the treatment of achalasia esophagus, reduces LES pressure. Our study shows that ISIB, even though injected into the LES, diffuses into the hiatus and causes its paralysis. These findings emphasize the importance of esophageal hiatus as an important component of the antireflux barrier and that the ISIB is refluxogenic.

Consensus-Based Care Recommendations for Pulmonologists Treating Adults with Myotonic Dystrophy Type 1.

PURPOSE OF REVIEW: Myotonic dystrophy type 1 (DM1) is a severe, progressive genetic disease that affects approximately 1 in 2,500 individuals globally [Ashizawa et al.: Neurol Clin Pract 2018;8(6):507-20]. In patients with DM1, respiratory muscle weakness frequently evolves, leading to respiratory failure as the main cause of death in this patient population, followed by cardiac complications [de Die-Smulders et al.: Brain 1998;121(Pt 8):1557-63], [Mathieu et al.: Neurology 1999;52(8):1658-62], [Groh et al.: Muscle Nerve 2011;43(5):648-51]. This paper provides a more detailed outline on the diagnostic and management protocols, which can guide pulmonologists who may not have experience with DM1 or who are not part of a neuromuscular multidisciplinary clinic. A group of neuromuscular experts in DM1 including pulmonologists, respiratory physiotherapists and sleep specialists discussed respiratory testing and management at baseline and during follow-up visits, based on their clinical experience with patients with DM1. The details are presented in this report. RECENT FINDINGS: Myotonic recruited 66 international clinicians experienced in the treatment of people living with DM1 to develop and publish consensus-based care recommendations targeting all body systems affected by this disease [Ashizawa et al.: Neurol Clin Pract. 2018;8(6):507-20]. Myotonic then worked with 12 international respiratory therapists, pulmonologists and neurologists with long-standing experience in DM respiratory care to develop consensus-based care recommendations for pulmonologists using a methodology called the Single Text Procedure. This process generated a 7-page document that provides detailed respiratory care recommendations for the management of patients living with DM1. This consensus is completely based on expert opinion and not backed up by empirical evidence due to limited clinical care data available for respiratory care management in DM patients. Nevertheless, we believe it is of relevance for professionals treating adults with myotonic dystrophy because it addresses practical issues related to respiratory management and care, which have been adapted to meet the specific issues in patients with DM1. SUMMARY: The resulting recommendations are intended to improve respiratory care for the most vulnerable of DM1 patients and lower the risk of untoward respiratory complications and mortality by providing pulmonologist who are less experienced with DM1 with practical indications on which tests and when to perform them, adapting the general respiratory knowledge to specific issues related to this multiorgan disease.

Association Between Diaphragmatic Paralysis and Ipsilateral Cervical Spondylosis on MRI.

PURPOSE: Diaphragmatic paralysis (DP) is an important cause of dyspnea with many underlying etiologies; however, frequently no cause is identified despite extensive investigation. We hypothesized that cervical spondylosis (CS), as manifest by cervical neuroforaminal stenosis on magnetic resonance imaging (MRI), is an underrecognized cause of unilateral DP. METHODS: A retrospective study was performed assessing cervical spine imaging utilization in the investigation of unilateral DP, and the contribution of CS to its pathogenesis. To assess the relationship between CS and DP, comparison was made between severity of ipsilateral and contralateral foraminal stenosis on cervical spine MRI in individuals with idiopathic DP, and to controls with DP of known etiology. RESULTS: Record searches identified 334 individuals with DP who were classified as idiopathic (n = 101) or DP of known etiology (n = 233). Of those with idiopathic DP, only 37% had undergone cervical spine imaging. Cervical spine MRIs, available for 32 individuals from the total cohort identified (n = 15 idiopathic DP, n = 17 DP of known etiology), were reviewed and severity of CS graded (0-2). In idiopathic DP, CS was significantly more severe (grade 2 stenosis) on the side of DP at C3-C4 (73% affected vs 13% unaffected side; p = 0.031) and C4-C5 (60% affected vs 20% unaffected side; p = 0.0039), while no difference was observed in DP of known etiology. Overall severity of CS across all cervical spine levels was significantly worse in idiopathic DP versus those with DP of known etiology. CONCLUSIONS: In unilateral idiopathic DP, severity of CS is associated with DP laterality and is an underrecognized cause of diaphragmatic dysfunction. We propose that evaluation of 'idiopathic' DP should routinely include cervical spine imaging, preferably by MRI.

3,4-diaminopyridine reverses paralysis in botulinum neurotoxin-intoxicated diaphragms through two functionally distinct mechanisms.

Botulinum neurotoxins (BoNTs) are exceedingly potent neurological poisons that prevent neurotransmitter release from peripheral nerve terminals by cleaving presynaptic proteins required for synaptic vesicle fusion. The ensuing neuromuscular paralysis causes death by asphyxiation. Although no antidotal treatments exist to block toxin activity within the nerve terminal, aminopyridine antagonists of voltage-gated potassium channels have been proposed as symptomatic treatments for botulism toxemia. However, clinical evaluation of aminopyridines as symptomatic treatments for botulism has been inconclusive, in part because mechanisms responsible for reversal of paralysis in BoNT-poisoned nerve terminals are not understood. Here we measured the effects of 3,4-diaminopyridine (DAP) on phrenic nerve-elicited diaphragm contraction and end-plate potentials at various times after intoxication with BoNT serotypes A, B, or E. We found that DAP-mediated increases in quantal content promote neurotransmission from intoxicated nerve terminals through two functionally distinguishable mechanisms. First, DAP increases the probability of neurotransmission at non-intoxicated release sites. This mechanism is serotype-independent, becomes less effective as nerve terminals become progressively impaired, and remains susceptible to ongoing intoxication. Second, DAP elicits persistent production of toxin-resistant endplate potentials from nerve terminals fully intoxicated by BoNT/A, but not serotypes B or E. Since this effect appears specific to BoNT/A intoxication, we propose that DAP treatment enables BoNT/A-cleaved SNAP-25 to productively engage in fusogenic release by increasing the opportunity for low-efficiency fusion events. These findings have important implications for DAP as a botulism therapeutic by defining conditions under which DAP may be clinically effective in reversing botulism symptoms.

Unilateral diaphragm paralysis: a dysfunction restricted not just to one hemidiaphragm.

BACKGROUND: Most patients with unilateral diaphragm paralysis (UDP) have unexplained dyspnea, exercise limitations, and reduction in inspiratory muscle capacity. We aimed to evaluate the generation of pressure in each hemidiaphragm separately and its contribution to overall inspiratory strength. METHODS: Twenty-seven patients, 9 in right paralysis group (RP) and 18 in left paralysis group (LP), with forced vital capacity (FVC) < 80% pred, and 20 healthy controls (CG), with forced expiratory volume in 1 s (FEV1) > 80% pred and FVC > 80% pred, were evaluated for lung function, maximal inspiratory (MIP) and expiratory (MEP) pressure measurements, diaphragm ultrasound, and transdiaphragmatic pressure during magnetic phrenic nerve stimulation (PdiTw). RESULTS: RP and LP had significant inspiratory muscle weakness compared to controls, detected by MIP (- 57.4 ± 16.9 for RP; - 67.1 ± 28.5 for LP and - 103.1 ± 30.4 cmH2O for CG) and also by PdiTW (5.7 ± 4 for RP; 4.8 ± 2.3 for LP and 15.3 ± 5.7 cmH2O for CG). The PdiTw was reduced even when the non-paralyzed hemidiaphragm was stimulated, mainly due to the low contribution of gastric pressure (around 30%), regardless of whether the paralysis was in the right or left hemidiaphragm. On the other hand, in CG, esophagic and gastric pressures had similar contribution to the overall Pdi (around 50%). Comparing both paralyzed and non-paralyzed hemidiaphragms, the mobility during quiet and deep breathing, and thickness at functional residual capacity (FRC) and total lung capacity (TLC), were significantly reduced in paralyzed hemidiaphragm. In addition, thickness fraction was extremely diminished when contrasted with the non-paralyzed hemidiaphragm. CONCLUSIONS: In symptomatic patients with UDP, global inspiratory strength is reduced not only due to weakness in the paralyzed hemidiaphragm but also to impairment in the pressure generated by the non-paralyzed hemidiaphragm.

Topical Ice Slush Adversely Affects Sniff Nasal Inspiratory Force After Coronary Bypass Surgery.

BACKGROUND: Topical cooling with ice slush as an adjunct for myocardial protection during cardiac surgery has been shown to cause freezing injury of the phrenic nerves. This can cause diaphragmatic dysfunction and respiratory complications. METHODS: Twenty (n=20) male patients between the ages of 40 and 60 years were equally randomised to undergo elective coronary artery bypass grafting (CABG) with either cold cardioplegic arrest with topical ice slush cooling or cold cardioplegic arrest without the use of ice slush. The sniff nasal inspiratory force (SNIF) was used to compare inspiratory muscle strength. RESULTS: There was no difference in the preoperative SNIF in the two randomised groups. In the immediate postoperative period, the ice slush group had worse SNIF (33.5±9.6cm H2O versus 47.8±12.2cm H2O; p=0.009). The pre-home discharge SNIF was still significantly lower for the ice slush group despite a noted improvement in SNIF recovery in both groups (38.3±10.6cm H2O versus 53.5±13.2cm H2O; p=0.011). Two patients in the ice slush group had left diaphragmatic dysfunction with none in the control group. CONCLUSION: The use of topical ice slush is associated with freezing injury of the phrenic nerves. This will adversely affect the inspiratory muscle force which may lead to respiratory complications after surgery.

Transporter Protein-Coupled DPCPX Nanoconjugates Induce Diaphragmatic Recovery after SCI by Blocking Adenosine A1 Receptors.

Respiratory complications in patients with spinal cord injury (SCI) are common and have a negative impact on the quality of patients' lives. Systemic administration of drugs that improve respiratory function often cause deleterious side effects. The present study examines the applicability of a novel nanotechnology-based drug delivery system, which induces recovery of diaphragm function after SCI in the adult rat model. We developed a protein-coupled nanoconjugate to selectively deliver by transsynaptic transport small therapeutic amounts of an A1 adenosine receptor antagonist to the respiratory centers. A single administration of the nanoconjugate restored 75% of the respiratory drive at 0.1% of the systemic therapeutic drug dose. The reduction of the systemic dose may obviate the side effects. The recovery lasted for 4 weeks (the longest period studied). These findings have translational implications for patients with respiratory dysfunction after SCI. SIGNIFICANCE STATEMENT: The leading causes of death in humans following SCI are respiratory complications secondary to paralysis of respiratory muscles. Systemic administration of methylxantines improves respiratory function but also leads to the development of deleterious side effects due to actions of the drug on nonrespiratory sites. The importance of the present study lies in the novel drug delivery approach that uses nanotechnology to selectively deliver recovery-inducing drugs to the respiratory centers exclusively. This strategy allows for a reduction in the therapeutic drug dose, which may reduce harmful side effects and markedly improve the quality of life for SCI patients.

Neuromuscular weakness in chronic obstructive pulmonary disease: chest wall, diaphragm, and peripheral muscle contributions.

PURPOSE OF REVIEW: Chronic obstructive lung disease affects the lung parenchyma and airways leading to well described effects in respiratory function. This review describes the current knowledge and advances regarding neuromuscular function and chest wall mechanics, which are affected in chronic obstructive pulmonary disease (COPD). RECENT FINDINGS: In COPD, progressive lung hyperinflation becomes constrained by a chest wall with decreasing capacity to expand, resulting in respiratory muscle inefficiency. There is evidence of neuromuscular uncoupling, that is, the respiratory muscle is unable to increase its output in proportion to increasing neural signals. COPD patients also have evidence of altered peripheral muscles function. The end effect of all these pathological changes is neuromuscular weakness. SUMMARY: Respiratory and peripheral muscles dysfunction is found in patients with COPD. This manifests clinically as dyspnea, poor exercise capacity, and decreased quality of life. We have clear evidence that rehabilitation helps several aspects of patients with COPD. Further understanding of the physiopathology is needed to improve our therapeutic and rehabilitation strategies.

Effect of Interscalene Brachial Plexus Block on the Pulmonary Function of Obese Patients: A Prospective, Observational Cohort Study.

BACKGROUND: The effect of interscalene block (ISB) on pulmonary function of obese participants has not been investigated. The goal of this study is to assess the association of obesity (body mass index [BMI] >29 kg/m vs BMI <25 kg/m) and change in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) after ISB in participants undergoing outpatient shoulder surgery. METHODS: This prospective, observational cohort study compared obese (BMI >29 kg/m) and normal-weight (BMI <25 kg/m) groups undergoing ISB for ambulatory shoulder surgery, on preblock and postblock FVC and FEV1, at 30 minutes postblock and in the postanesthesia care unit (PACU). The primary outcome in this study was FVC% change (percentage change from preblock to postblock values of FVC) at 30 minutes postblock in the supine position. Secondary outcomes included FVC% change at PACU and in the sitting position, FEV1% change (percentage change from preblock to postblock values of FEV1), FVC, FEV1, incidence of diaphragmatic paresis, modified Borg scale for perceived dyspnea, Richmond Agitation-Sedation Scale scores for sedation, and intraoperative airway events. RESULTS: Fourteen participants were recruited to each group. The mean (standard deviation) BMI in the normal-weight and obese groups was 23 (1.7) and 33 (3.1) kg/m, respectively. ISB success rate was 100%. All participants demonstrated hemidiaphragmatic paresis after ISB. Compared to the normal-weight group, in the sitting position, the obese group had a significant decrease in FVC% change at 30 minutes (-30 [10.5] vs -23 [7.2], P = .046) and an FEV1% change in the PACU (-40 [12.6] vs -27 [13.9], P = .02). No difference was found for measurements taken in the supine position. A repeated-measures analysis demonstrated that, adjusted for position, there is no significant group effect on FVC% change or FEV1% change from 30 minutes to PACU. The 2 groups were not different in terms of breathlessness and sedation at 30 minutes (P = .67, P = .48, respectively) and in the PACU (P = .69, P > .99, respectively) nor in the occurrence of intraoperative airway events (P > .99). CONCLUSIONS: ISB is associated with greater FVC and FEV1 reductions in obese participants undergoing shoulder surgery compared to normal-weight participants. Neither time (30 minutes versus PACU) nor position (sitting versus supine) affected this relationship. Despite these changes, obesity was not associated with increased clinical respiratory symptoms or events.

The Maximal Expiratory-to-Inspiratory Pressure Ratio and Supine Vital Capacity as Screening Tests for Diaphragm Dysfunction.

PURPOSE: The change in vital capacity from the seated to supine position (∆VC-supine) is used to screen for diaphragm dysfunction (DD), but some individuals are unable to tolerate the supine position. Since expiratory muscle function is often preserved in patients with isolated DD and inspiratory strength is reduced, the purpose of this study was to examine if the ratio of maximal expiratory pressure to maximal inspiratory pressure (MEP/MIP) may provide an alternative to ∆VC-supine when screening patients for DD. METHODS: We performed a cross-sectional analysis on 76 patients referred for evaluation of unexplained dyspnea and possible DD. MEP and MIP were measured in the seated position as well as the percent change in VC from the seated to supine position (∆VC-supine %). The presence of unilateral diaphragm paralysis (UDP), bilateral diaphragm paralysis (BDP), or normal diaphragm function (N) was confirmed by ultrasound. RESULTS: Of the 76 patients, 23 had N, 40 had UDP, and 13 had BDP. MEP/MIP was significantly greater for UDP compared to N (2.1(1.2-5.7) and 1.5(0.7-2.2), respectively) (median and interquartile range) and for BDP compared to UDP (4.3(2.3-7.5) and 2.1(1.2-5.7), respectively) (p < 0.001). The area (AUC) under the receiver-operating characteristic curve for MEP/MIP between N and UDP was 0.84 (95% confidence interval (CI) 0.74-0.94) and between UDP and BDP was 0.90 (95% CI 0.80-0.99). MEP/MIP had a strong monotonic relationship with ∆VC-supine % (Spearman's ρ = 0.68, p < 0.001). CONCLUSIONS: The MEP/MIP ratio provides a method with comparable sensitivity and specificity to ∆VC-supine % that can be used to screen patients with suspected isolated phrenic neuropathy and alleviates the need for measuring supine pulmonary function.

Ultrasound for diaphragmatic dysfunction in postoperative cardiac children.

Introduction The use of ultrasound for assessing diaphragmatic dysfunction after paediatric cardiac surgery may be under-utilised. This study aimed to evaluate the role of bedside ultrasound performed by an intensivist to diagnose diaphragmatic dysfunction and the need for plication after paediatric cardiac surgery. METHODS: We carried out a retrospective cohort study on prospectively collected data of postoperative children admitted to the paediatric cardiac ICU during 2013. Diaphragmatic dysfunction was suspected based on difficulties in weaning from positive pressure ventilation or chest X-ray findings. Ultrasound studies were performed by the paediatric cardiac ICU intensivist and confirmed by a qualified radiologist. RESULTS: Out of 344 postoperative patients, 32 needed diaphragm ultrasound for suspected dysfunction. Ultrasound studies confirmed diaphragmatic dysfunction in 17/32 (53%) patients with an average age and weight of 10.8±3.8 months and 6±1 kg, respectively. The incidence rate of diaphragmatic dysfunction was 4.9% in relation to the whole population. Diaphragmatic plication was needed in 9/17 cases (53%), with a rate of 2.6% in postoperative cardiac children. The mean plication time was 15.1±1.3 days after surgery. All patients who underwent plication were under 4 months of age. After plication, they were discharged with mean paediatric cardiac ICU and hospital stay of 19±3.5 and 42±8 days, respectively. CONCLUSIONS: Critical-care ultrasound assessment of diaphragmatic movement is a useful and practical bedside tool that can be performed by a trained paediatric cardiac ICU intensivist. It may help in the early detection and management of diaphragmatic dysfunction after paediatric cardiac surgery through a decision-making algorithm that may have potential positive effects on morbidity and outcome.

Long-Term Follow-Up after Phrenic Nerve Reconstruction for Diaphragmatic Paralysis: A Review of 180 Patients.

Background Phrenic nerve reconstruction has been evaluated as a method of restoring functional activity and may be an effective alternative to diaphragm plication. Longer follow-up and a larger cohort for analysis are necessary to confirm the efficacy of this procedure for diaphragmatic paralysis. Methods A total of 180 patients treated with phrenic nerve reconstruction for chronic diaphragmatic paralysis were followed for a median 2.7 years. Assessment parameters included: 36-Item Short Form Health Survey (SF-36) physical functioning survey, spirometry, chest fluoroscopy, electrodiagnostic evaluation, a five-item questionnaire to assess specific functional issues, and overall patient-reported outcome. Results Overall, 134 males and 46 females with an average age of 56 years (range: 10-79 years) were treated. Mean baseline percent predicted values for forced expiratory volume in 1 second, forced vital capacity, vital capacity, and total lung capacity, were 61, 63, 67, and 75%, respectively. The corresponding percent improvements in percent predicted values were: 11, 6, 9, and 13% (p ≤ 0.01; ≤ 0.01; ≤ 0.05; ≤ 0.01). Mean preoperative SF-36 physical functioning survey scores were 39%, and an improvement to 65% was demonstrated following surgery (p ≤ 0.0001). Nerve conduction latency, improved by an average 23% (p ≤ 0.005), and there was a corresponding 125% increase in diaphragm motor amplitude (p ≤ 0.0001). A total of 89% of patients reported an overall improvement in breathing function. Conclusion Long-term assessment of phrenic nerve reconstruction for diaphragmatic paralysis indicates functional correction and symptomatic relief.

Ventilator-induced diaphragmatic dysfunction: what have we learned?

PURPOSE OF REVIEW: The purpose of the review is to summarize and discuss recent research regarding the role of mechanical ventilation in producing weakness and atrophy of the diaphragm in critically ill patients, an entity termed ventilator-induced diaphragmatic dysfunction (VIDD). RECENT FINDINGS: Severe weakness of the diaphragm is frequent in mechanically ventilated patients, in whom it contributes to poor outcomes including increased mortality. Significant progress has been made in identifying the molecular mechanisms responsible for VIDD in animal models, and there is accumulating evidence for occurrence of the same cellular processes in the diaphragms of human patients undergoing prolonged mechanical ventilation. SUMMARY: Recent research is pointing the way to novel pharmacologic therapies as well as nonpharmacologic methods for preventing VIDD. The next major challenge in the field will be to move these findings from the bench to the bedside in critically ill patients.

Diaphragmatic Dysfunction after Thoracic Operations.

The perioperative management of diaphragmatic weakness and phrenic nerve dysfunction is complex, due to varied etiologies and clinical presentations. The factors leading to diaphragmatic weakness may culminate after the operation with transient or persistent respiratory failure. This review discusses diaphragmatic disorders and postoperative respiratory failure caused by unilateral or bilateral diaphragmatic impairment. The origins of neuromuscular weakness involving the diaphragm are diverse, and often lie within the domains of different medical specialties, with only a portion of the condition related to surgical intervention. Consideration of underlying etiologies for any individual patient requires thorough multidisciplinary review. The most important clinical scenarios compounding diaphragmatic weakness, including acute myasthenic states, persistent neuromuscular blockade, and surgical injury to the phrenic nerve or diaphragm, are accessible to attentive surgeons. Awareness of the signs and symptoms of undiagnosed weakness, preoperative pursuit of its diagnosis, knowledge of surgical alternatives to phrenic nerve resection, and cooperative skills in the multidisciplinary management of myasthenia all are crucial to improve patient outcomes.

To Sink the Lifted: Selection, Technique, and Result of Laparoscopic Diaphragmatic Plication for Paralysis or Eventration.

Introduction Diaphragmatic eventration is a congenital defect of the muscular portion of a hemidiaphragm that eventually leads to hemidiaphragmatic elevation and dysfunction. The clinical diagnosis of diaphragmatic eventration or diaphragmatic paralysis may be indistinguishable and diaphragmatic plication is the treatment of choice for both conditions. Discussion We review the indications, patient selection, and surgical techniques for diaphragmatic plication. We explain our preferred technique and guide the reader step by step on our approach. Conclusion Minimally invasive diaphragm plication techniques are effective alternatives to open transthoracic plication and result in significant improvement in dyspnea and quality of life in adequately selected patients.

Video-Assisted Minithoracotomy Diaphragmatic Plication: Respiratory Effects in Adults.

Objectives The objective of this study was to analyze the clinical respiratory and spirometric effects of video-assisted minithoracotomy diaphragmatic plication (VAM-T DP) in the treatment of diaphragmatic eventration. Methods A retrospective longitudinal study of 18 patients who underwent a VAM-T DP in our service between February 2005 and July 2011 was performed. Data of patient characteristics, preoperative clinical variables, and postoperative results (3, 6, and 12 months) were collected for statistical analysis using the software package SPSS 13.0 for Windows (Wilcoxon test, Friedman test, and Z-test). Results The main clinical respiratory and spirometric variables improved significantly and remained stable over 1 year. Conclusions VAM-T DP is a viable and safe procedure that improves the spirometry values and offers stable results during the first year. To our knowledge, the present series is the second largest published report in English relating to this procedure in adults.

Time-Trend Analysis of Pulmonary and Diaphragmatic Functionality in Patients with Diaphragmatic Palsy or with Chronic Diaphragmatic Hernia after Surgical Treatment.

Background The aim of this study was to assess long-term pulmonary and diaphragmatic function in two cohorts of patients: the first one affected by diaphragmatic palsy (DP) who underwent plication reinforced by rib-fixed mesh and the second one affected by chronic diaphragmatic hernia (TDH) who underwent surgical reduction and direct suture. Materials and Methods From 1996 to 2011, 10 patients with unilateral DP and 6 patients with TDH underwent elective surgery. Preoperative and long-term (12 months) follow-up assessments were completed in all patients, including pulmonary function tests (PFTs) with diffusion of the lung for carbon monoxide (DLCO), measure of maximum inspiratory pressure (MIP) assessed both in standing and in supine positions, blood gas analysis, chest computed tomographic (CT) scan, and dyspnea score. The Pearson chi-square test, Fisher exact test, and Student t-test were applied when indicated. Results At long-term (12 months) postoperative follow-up, patients operated for DP showed a significant improvement in terms of forced expiratory volume in 1 second (FEV1%) (+ 18.2%, p < 0.001), forced vital capacity (FVC%) (+ 12.8%, p < 0.001), DLCO% (+ 8.3%, p = 0.04), and Po 2 (+ 9.86 mm Hg, p < 0.001) when compared with baseline values. Conversely, when considering the TDH group, only the levels of Po 2 were found to be significantly higher in the postoperative assessment (+ 8.3 mm Hg, p = 0.04). Although MIP increased in both the groups after surgery, a persistent and significant decrease of MIP was detected in TDH group when comparing the levels assessed in supine position with those measured in the standing position (p < 0.001). Medical Research Council dyspnea scale improved in the DP group by a factor of 0.80 (p < 0.001) and in the TDH group by a factor of 0.33 (p = 0.175). Conclusion In patients who underwent surgery for DP, good long-term results may be predicted in terms of pulmonary flows, volumes, and DLCO. Conversely, in patients who underwent elective surgery for chronic TDH, a persistent overall restrictive pattern, lower MIP values in supine position, and paradoxical motion could be expected.