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1.
Am J Physiol Gastrointest Liver Physiol ; 318(1): G77-G83, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31589467

RESUMO

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.


Assuntos
Inibidores da Liberação da Acetilcolina/efeitos adversos , Toxinas Botulínicas Tipo A/efeitos adversos , Diafragma/efeitos dos fármacos , Acalasia Esofágica/tratamento farmacológico , Esfíncter Esofágico Inferior/efeitos dos fármacos , Refluxo Gastroesofágico/induzido quimicamente , Contração Muscular/efeitos dos fármacos , Paralisia Respiratória/induzido quimicamente , Inibidores da Liberação da Acetilcolina/administração & dosagem , Adulto , Idoso , Toxinas Botulínicas Tipo A/administração & dosagem , Diafragma/fisiopatologia , Acalasia Esofágica/diagnóstico , Acalasia Esofágica/fisiopatologia , Esfíncter Esofágico Inferior/fisiopatologia , Feminino , Refluxo Gastroesofágico/diagnóstico , Refluxo Gastroesofágico/fisiopatologia , Humanos , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Pressão , Paralisia Respiratória/diagnóstico , Paralisia Respiratória/fisiopatologia , Fatores de Risco
3.
Pulm Med ; 2019: 1090982, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057965

RESUMO

Purpose: Healthy patients with unilateral diaphragm paralysis (UDP) are often asymptomatic; those with UDP and comorbidities that increase work of breathing are often dyspneic. We report the effect of obesity on exercise capacity in UDP patients. Methods: All obese and nonobese patients with UDP undergoing cardiopulmonary exercise testing (CPET) during a 32-month period in the exercise laboratory of an academic hospital were compared to a retrospectively identified cohort of obese and nonobese controls without UDP, matched for key features. CPET used a modified Bruce treadmill protocol with breath-to-breath expired gas analysis. O2 uptake, minute ventilation, exercise time, and work rate were recorded at peak exercise. Static pulmonary functions were measured. Kruskal-Wallis, Wilcoxon rank sum, and Fisher's exact tests were used to compare continuous and categorical variables, respectively. Stratified linear regression was used to quantify the effect of UDP and obesity on CPET variables. Results: Twenty-two UDP patients and 46 controls were studied. The BMI of obese and nonobese patients was 33.0±4.2 and 25.8±2.4 kg/m2, respectively. UDP subjects with obesity, compared to controls with neither condition, showed significantly reduced peak O2 uptake normalized to actual body weight (1.57±0.64 versus 2.01±0.88 L/min), shorter exercise time (5.7±2.0 versus 8.5±2.9 minutes), and lower peak ventilation. This was not observed in UDP alone or obesity alone. Peak work rate trended lower in the combined UDP-obesity group. Conclusion: Neither UDP nor obesity alone significantly reduced exercise capacity. Superimposed UDP and obesity interact to create a ventilatory limitation to exercise, with reduced peak-VO2, exercise time, and work rate.


Assuntos
Tolerância ao Exercício/fisiologia , Obesidade/fisiopatologia , Paralisia Respiratória/fisiopatologia , Limiar Anaeróbio/fisiologia , Índice de Massa Corporal , Estudos de Casos e Controles , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Testes de Função Respiratória
4.
Clin Physiol Funct Imaging ; 39(2): 143-149, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30325572

RESUMO

BACKGROUND: M-mode ultrasonography might be useful for detecting hemidiaphragm paralysis. The objective of the present study was to describe the motion recorded by M-mode ultrasonography of both diaphragmatic leaves in patients with a pre-established diagnosis of hemidiaphragm paralysis. METHODS: A study was conducted in 26 patients (18 men, 8 women) with unilateral diaphragmatic paralysis. They were referred to two different rehabilitation centres after thoracic surgery in 23 cases and cardiac interventional procedures in three cases. The pulmonary function tests and the study of the diaphragmatic motion using M-mode ultrasonography were recorded. RESULTS: The pulmonary function tests showed a restrictive pattern. The M-mode ultrasonography reported either the absence of motion or a weak paradoxical (cranial) displacement (less than 0·5 cm) of the paralysed hemidiaphragm during quiet breathing. A paradoxical motion was recorded in all patients during voluntary sniffing, reaching around -1 cm. During deep breathing, a paradoxical motion at the beginning of the inspiration was observed. Thereafter, a re-establishment of the motion in the craniocaudal direction was recorded. The excursions measured on the healthy side, during quiet breathing and voluntary sniffing, were increased in patients suffering from contralateral hemidiaphragm paralysis, when compared with 170 healthy volunteers. CONCLUSIONS: To detect diaphragmatic dysfunction in patients at risk, it would be useful to study diaphragmatic motion by M-mode ultrasonography during quiet breathing, voluntary sniffing and deep breathing.


Assuntos
Diafragma/diagnóstico por imagem , Paralisia Respiratória/diagnóstico por imagem , Ultrassonografia/métodos , Adulto , Idoso , Diafragma/fisiopatologia , Feminino , França , Humanos , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Movimentos dos Órgãos , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Respiração , Testes de Função Respiratória , Paralisia Respiratória/fisiopatologia
5.
J Comp Neurol ; 526(18): 2973-2983, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30411341

RESUMO

Structural plasticity in motoneurons may be influenced by activation history and motoneuron-muscle fiber interactions. The goal of this study was to examine the morphological adaptations of phrenic motoneurons following imposed motoneuron inactivity while controlling for diaphragm muscle inactivity. Well-characterized rat models were used including unilateral C2 spinal hemisection (SH; ipsilateral phrenic motoneurons and diaphragm muscle are inactive) and tetrodotoxin phrenic nerve blockade (TTX; ipsilateral diaphragm muscle is paralyzed while phrenic motoneuron activity is preserved). We hypothesized that inactivity of phrenic motoneurons would result in a decrease in motoneuron size, consistent with a homeostatic increase in excitability. Phrenic motoneurons were retrogradely labeled by ipsilateral diaphragm muscle injection of fluorescent dextrans or cholera toxin subunit B. Following 2 weeks of diaphragm muscle paralysis, morphological parameters of labeled ipsilateral phrenic motoneurons were assessed quantitatively using fluorescence confocal microscopy. Compared to controls, phrenic motoneuron somal volumes and surface areas decreased with SH, but increased with TTX. Total phrenic motoneuron surface area was unchanged by SH, but increased with TTX. Dendritic surface area was estimated from primary dendrite diameter using a power equation obtained from three-dimensional reconstructed phrenic motoneurons. Estimated dendritic surface area was not significantly different between control and SH, but increased with TTX. Similarly, TTX significantly increased total phrenic motoneuron surface area. These results suggest that ipsilateral phrenic motoneuron morphological adaptations are consistent with a normalization of motoneuron excitability following prolonged alterations in motoneuron activity. Phrenic motoneuron structural plasticity is likely more dependent on motoneuron activity (or descending input) than muscle fiber activity.


Assuntos
Neurônios Motores/patologia , Plasticidade Neuronal/fisiologia , Paralisia Respiratória/patologia , Paralisia Respiratória/fisiopatologia , Animais , Diafragma/inervação , Modelos Animais de Doenças , Nervo Frênico/patologia , Nervo Frênico/fisiopatologia , Ratos , Ratos Sprague-Dawley
8.
BMC Pulm Med ; 18(1): 126, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30068327

RESUMO

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.


Assuntos
Diafragma/diagnóstico por imagem , Diafragma/fisiopatologia , Pressão , Paralisia Respiratória/fisiopatologia , Adulto , Idoso , Estudos de Casos e Controles , Estudos Transversais , Feminino , Volume Expiratório Forçado , Capacidade Residual Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Nervo Frênico/fisiopatologia , Paralisia Respiratória/patologia , Ultrassonografia , Capacidade Vital
9.
Chest ; 154(6): 1395-1403, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30144420

RESUMO

The diaphragm is the primary muscle of inspiration. Its capacity to respond to the load imposed by pulmonary disease is a major determining factor both in the onset of ventilatory failure and in the ability to successfully separate patients from ventilator support. It has recently been established that a very large proportion of critically ill patients exhibit major weakness of the diaphragm, which is associated with poor clinical outcomes. The two greatest risk factors for the development of diaphragm weakness in critical illness are the use of mechanical ventilation and the presence of sepsis. Loss of force production by the diaphragm under these conditions is caused by a combination of defective contractility and reduced diaphragm muscle mass. Importantly, many of the same molecular mechanisms are implicated in the diaphragm dysfunction associated with both mechanical ventilation and sepsis. This review outlines the primary cellular mechanisms identified thus far at the nexus of diaphragm dysfunction associated with mechanical ventilation and/or sepsis, and explores the potential for treatment or prevention of diaphragm weakness in critically ill patients through therapeutic manipulation of these final common pathway targets.


Assuntos
Estado Terminal , Administração dos Cuidados ao Paciente/métodos , Respiração Artificial/efeitos adversos , Paralisia Respiratória , Sepse/complicações , Humanos , Paralisia Respiratória/etiologia , Paralisia Respiratória/fisiopatologia , Paralisia Respiratória/terapia
10.
BMJ Case Rep ; 20182018 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-29754137

RESUMO

We report a preterm neonate born with respiratory distress. The neonate was found to have diaphragmatic palsy and brachial palsy. The neonate was born by caesarean section and there was no history of birth trauma. On examination, there was bilateral congenital talipes equinovarus and a scar was present on the forearm. The mother had a history of chickenpox during the 16 weeks of pregnancy for which no treatment was sought. On investigation, PCR for varicella was found to be positive in the neonate.


Assuntos
Neuropatias do Plexo Braquial/virologia , Varicela/congênito , Pé Torto Equinovaro/virologia , Doenças Fetais/virologia , Antebraço/anormalidades , Complicações Infecciosas na Gravidez/virologia , Paralisia Respiratória/virologia , Aciclovir/uso terapêutico , Antibacterianos/uso terapêutico , Neuropatias do Plexo Braquial/fisiopatologia , Neuropatias do Plexo Braquial/terapia , Moldes Cirúrgicos , Cesárea , Varicela/transmissão , Pé Torto Equinovaro/terapia , Feminino , Doenças Fetais/fisiopatologia , Humanos , Recém-Nascido , Transmissão Vertical de Doença Infecciosa , Masculino , Mães , Gravidez , Complicações Infecciosas na Gravidez/fisiopatologia , Paralisia Respiratória/fisiopatologia , Paralisia Respiratória/terapia , Resultado do Tratamento
11.
Rev. esp. anestesiol. reanim ; 65(2): 81-89, feb. 2018. tab, ilus, graf
Artigo em Espanhol | IBECS | ID: ibc-170011

RESUMO

Introducción. La parálisis diafragmática es un efecto indeseable clásicamente asociado al bloqueo interescalénico. De forma reciente ha sido introducido en clínica el índice del grosor del músculo diafragma (grosor inspiratorio/grosor espiratorio) obtenido mediante ecografía como herramienta diagnóstica en la parálisis crónica y atrofia del músculo diafragma. Nuestro objetivo fue evaluar este índice para el diagnóstico de paresia frénica aguda asociada al bloqueo interescalénico. Pacientes y métodos. Diseñamos un estudio observacional descriptivo en 22 pacientes programados para artroscopia de hombro. Se les realizó una espirometría forzada (se consideró paresia frénica un descenso del FVC y FEV1 ≥20%), se identificó la zona de aposición en la línea axilar anterior y se evaluó el desplazamiento diafragmático en inspiración y espiración máximas (n.° de espacios intercostales; se consideró paresia frénica una reducción ≥25%) y el grosor del músculo diafragma (se consideró paresia frénica un índice<1,2). Estas determinaciones se realizaron antes y a los 20 min de realizar el bloqueo interescalénico entre C5 y C6 con 20ml de ropivacaína 0,5%. Resultados. Veintiún pacientes (95%) presentaron bloqueo del nervio frénico según alguno o varios de los métodos empleados. Un paciente no manifestó ningún síntoma ni signo sugestivo de parálisis frénica y fue excluido del análisis posterior. Todos los pacientes presentaron paresia frénica con base en el índice del grosor diafragmático, con un índice prebloqueo de 1,8±0,5 y posbloqueo de 1,05±0,06 (p<0,001). El 90% de los pacientes (19) presentó paresia frénica según la espirometría y todos los pacientes presentaron un descenso diafragmático reducido tras el bloqueo (de 1,9±0,5 espacios intercostales a 0,5±0,3; p<0,001). Conclusión. El índice del grosor diafragmático en inspiración/espiración<1,2 parece ser de utilidad en el diagnóstico de paresia frénica asociada al bloqueo interescalénico, sin que sea necesaria una evaluación basal prebloqueo (AU)


Introduction. Diaphragmatic paralysis is a side-effect associated with interscalene block. Thickness index of the diaphragm muscle (inspiratory thickness/expiratory thickness) obtained by ultrasound has recently been introduced in clinical practice for diagnosis of diaphragm muscle atrophy. Our objective was to evaluate this index for the diagnosis of acute phrenic paresis associated with interscalene block. Patients and methods. We designed an observational study in 22 patients scheduled for shoulder arthroscopy. Spirometry was performed (criteria of phrenic paresis was a decrease in FVC and FEV1 ≥20%). Ultrasound apposition zone was assessed in anterior axillary line and diaphragmatic displacement was evaluated on inspiration and expiration (number of intercostal spaces; phrenic paresis considered a reduction ≥25%) and thickness of the diaphragm muscle (a phrenic paresis was considered an index <1.2). These determinations were performed before and at 20min after interscalene block at C5-C6 with 20ml of 0.5% ropivacaine. Results. Twenty-one patients (95%) presented phrenic nerve block according to one or more of the methods used. One patient did not show any symptoms or signs suggestive of phrenic paralysis and was excluded. All the patients presented phrenic paresis based on the diaphragmatic thickness index, with the pre-block index being 1.8±0.5 and post-block of 1.05±0.06 (P<0.001). Ninety percent of the patients (19) presented phrenic paresis according to spirometry and all the patients had a reduction in diaphragmatic movement after the block (from 1.9±0.5 intercostal spaces to 0.5±0.3; P<0.001). Conclusion. The index of inspiratory / expiratory diaphragmatic thickness at cut-off <1.2 seems to be useful in the diagnosis of phrenic paresis associated with interscalene block. This index does not require a baseline pre-assessment (AU)


Assuntos
Humanos , Paralisia Respiratória/fisiopatologia , Bloqueio Nervoso/efeitos adversos , Nervo Frênico , Plexo Braquial , Diafragma/diagnóstico por imagem , Epidemiologia Descritiva , Valor Preditivo dos Testes , Diagnóstico Diferencial
12.
Toxicol Appl Pharmacol ; 341: 77-86, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29366638

RESUMO

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.


Assuntos
4-Aminopiridina/análogos & derivados , Toxinas Botulínicas Tipo A/toxicidade , Diafragma/efeitos dos fármacos , Paralisia Respiratória/induzido quimicamente , Paralisia Respiratória/tratamento farmacológico , 4-Aminopiridina/farmacologia , 4-Aminopiridina/uso terapêutico , Amifampridina , Animais , Diafragma/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Bloqueadores dos Canais de Potássio/farmacologia , Bloqueadores dos Canais de Potássio/uso terapêutico , Paralisia Respiratória/fisiopatologia
13.
Asian Cardiovasc Thorac Ann ; 26(2): 94-100, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29363317

RESUMO

Background Procurement of the internal thoracic artery risks ipsilateral phrenic nerve injury and elevated hemidiaphragm. Anatomical variations increase the risk on the right side. Patients receiving left-sided in-situ right internal thoracic artery configurations appear to be at greatest risk. Methods From 2014 to 2016, 432 patients undergoing left-sided in-situ bilateral internal thoracic artery grafting were grouped according to right internal thoracic artery configuration: retroaortic via transverse sinus (77%) or ante-aortic (23%); targets were the circumflex and left anterior descending artery territories, respectively. Elevated hemidiaphragm was assessed by serial chest radiographs and categorized by side, complete (≥2 intercostal spaces) versus partial, and permanent versus transient. Results Right elevated hemidiaphragm occurred in 4.2% of patients. The incidence of radiological complete right elevated hemidiaphragm was 2.8% (12/432); 8 cases were transient with recovery in 3.5 ± 0.3 weeks. Permanent right elevated hemidiaphragm occurred in 0.9% (retroaortic group only). Permanent left elevated hemidiaphragm occurred in 0.9% and was significantly higher in the ante-aortic group (3/99 vs. 1/333, p = 0.039). No bilateral hemidiaphragm elevation was documented. Partial right elevated hemidiaphragm occurred in 1.4% and was not associated with adverse early or late respiratory outcomes. Conclusions Despite susceptible right phrenic nerve-internal thoracic artery anatomy, the incidence of permanent right elevated hemidiaphragm is low and no higher than left-sided in prone bilateral internal thoracic artery subsets. This reflects skeletonized internal thoracic artery procurement. Although statistical significance was not achieved, a retroaortic right internal thoracic artery configuration may constitute a higher risk of right phrenic nerve injury.


Assuntos
Diafragma/inervação , Anastomose de Artéria Torácica Interna-Coronária/efeitos adversos , Artéria Torácica Interna/anormalidades , Artéria Torácica Interna/cirurgia , Traumatismos dos Nervos Periféricos/epidemiologia , Nervo Frênico/lesões , Idoso , Diafragma/diagnóstico por imagem , Feminino , Humanos , Incidência , Anastomose de Artéria Torácica Interna-Coronária/métodos , Israel/epidemiologia , Masculino , Artéria Torácica Interna/diagnóstico por imagem , Pessoa de Meia-Idade , Traumatismos dos Nervos Periféricos/diagnóstico por imagem , Traumatismos dos Nervos Periféricos/fisiopatologia , Paralisia Respiratória/epidemiologia , Paralisia Respiratória/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
14.
Heart Lung Circ ; 27(3): 371-376, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28473213

RESUMO

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.


Assuntos
Ponte de Artéria Coronária , Diafragma/inervação , Hipotermia Induzida/efeitos adversos , Capacidade Inspiratória/fisiologia , Nervo Frênico/lesões , Insuficiência Respiratória/etiologia , Paralisia Respiratória/complicações , Administração Tópica , Adulto , Doença da Artéria Coronariana/cirurgia , Humanos , Hipotermia Induzida/métodos , Gelo , Masculino , Pessoa de Meia-Idade , Nariz , Período Pós-Operatório , Insuficiência Respiratória/fisiopatologia , Paralisia Respiratória/fisiopatologia
15.
Respir Physiol Neurobiol ; 248: 31-35, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29155335

RESUMO

PURPOSE: Diaphragm paresis (DP) is characterized by abnormalities of respiratory muscle function. However, the impact of DP on exercise capacity is not well known. This study was performed to assess exercise tolerance in patients with DP and to determine whether inspiratory muscle function was related to exercise capacity, ventilatory pattern and cardiovascular function during exercise. METHODS: This retrospective study included patients with DP who underwent both diaphragmatic force measurements, and cardiopulmonary exercise testing (CPET). RESULTS: Fourteen patients were included. Dyspnea was the main symptom limiting exertion (86%). Exercise capacity was slightly reduced (median VO2peak: 80% [74.5%-90.5%]), mostly due to ventilatory limitation. Diaphragm and overall inspiratory muscle function were correlated with exercise ventilation. Moreover, overall inspiratory muscle function was related with oxygen consumption (r=0.61) and maximal workload (r=0.68). CONCLUSIONS: DP decreases aerobic capacity due to ventilatory limitation. Diaphragm function is correlated with exercise ventilation whereas overall inspiratory muscle function is correlated with both exercise capacity and ventilation suggesting the importance of the accessory inspiratory muscles during exercise for patients with DP. Further larger prospective studies are needed to confirm these results.


Assuntos
Teste de Esforço , Exercício Físico/fisiologia , Músculos Respiratórios/fisiopatologia , Paralisia Respiratória/fisiopatologia , Idoso , Estudos de Coortes , Eletromiografia , Potencial Evocado Motor/fisiologia , Teste de Esforço/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Respiração , Testes de Função Respiratória
16.
Rev Esp Anestesiol Reanim ; 65(2): 81-89, 2018 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29126611

RESUMO

INTRODUCTION: Diaphragmatic paralysis is a side-effect associated with interscalene block. Thickness index of the diaphragm muscle (inspiratory thickness/expiratory thickness) obtained by ultrasound has recently been introduced in clinical practice for diagnosis of diaphragm muscle atrophy. Our objective was to evaluate this index for the diagnosis of acute phrenic paresis associated with interscalene block. PATIENTS AND METHODS: We designed an observational study in 22 patients scheduled for shoulder arthroscopy. Spirometry was performed (criteria of phrenic paresis was a decrease in FVC and FEV1 ≥20%). Ultrasound apposition zone was assessed in anterior axillary line and diaphragmatic displacement was evaluated on inspiration and expiration (number of intercostal spaces; phrenic paresis considered a reduction ≥25%) and thickness of the diaphragm muscle (a phrenic paresis was considered an index <1.2). These determinations were performed before and at 20min after interscalene block at C5-C6 with 20ml of 0.5% ropivacaine. RESULTS: Twenty-one patients (95%) presented phrenic nerve block according to one or more of the methods used. One patient did not show any symptoms or signs suggestive of phrenic paralysis and was excluded. All the patients presented phrenic paresis based on the diaphragmatic thickness index, with the pre-block index being 1.8±0.5 and post-block of 1.05±0.06 (P<0.001). Ninety percent of the patients (19) presented phrenic paresis according to spirometry and all the patients had a reduction in diaphragmatic movement after the block (from 1.9±0.5 intercostal spaces to 0.5±0.3; P<0.001). CONCLUSION: The index of inspiratory / expiratory diaphragmatic thickness at cut-off <1.2 seems to be useful in the diagnosis of phrenic paresis associated with interscalene block. This index does not require a baseline pre-assessment.


Assuntos
Bloqueio do Plexo Braquial/efeitos adversos , Diafragma/diagnóstico por imagem , Nervo Frênico/fisiopatologia , Paralisia Respiratória/etiologia , Adulto , Idoso , Anestésicos Locais/efeitos adversos , Diafragma/patologia , Procedimentos Cirúrgicos Eletivos , Expiração , Feminino , Volume Expiratório Forçado , Humanos , Inalação , Masculino , Pessoa de Meia-Idade , Movimento , Atrofia Muscular/diagnóstico por imagem , Paralisia Respiratória/diagnóstico por imagem , Paralisia Respiratória/patologia , Paralisia Respiratória/fisiopatologia , Ombro/cirurgia , Ultrassonografia , Capacidade Vital
18.
Innovations (Phila) ; 12(6): 398-405, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29219945

RESUMO

OBJECTIVE: The aim of the study was to report the safety and efficacy of video-assisted thoracoscopic (VATS) plication of the diaphragm at our institution between 2006 and 2016. METHODS: Adult patients selected on etiology and combination of investigations including plain chest x-ray, computed tomography of chest and abdomen, lung functions in supine and sitting positions, radiological/ultrasonic screening for diaphragmatic movement, and phrenic nerve conduction studies. We incorporated a triportal VATS and Endostitch device for plication, using CO2 insufflation to maximum 12 mm Hg. Bilateral simultaneous plication and high-risk patients were electively admitted to intensive therapy unit postoperatively. RESULTS: Thirty-five patients (24 males) had their diaphragm plicated. The mean age was 56.6 years (range = 23-76 years). The mean body mass index was 32.1 (range = 22.2-45.4). Twenty one were right, 13 left, 2 patients had VATS simultaneous bilateral plication, and 1 had sequential VATS bilateral plication. Paralysis was idiopathic in 17, posttraumatic in 5, postremoval of mediastinal tumor in 4, and postcardiac surgery in 3. All patients presented with lifestyle-limiting dyspnea and orthopnea, three were on nocturnal noninvasive ventilation. Five were diabetic and 16 were smokers. The mean supine forced expiratory volume in the first second was 62.5% of predicted. Twenty two were performed by VATS (63%), three converted to thoracotomy, and 13 were open limited thoracotomy (historic). The mean hospital stay was 4.5 days (range = 1-18, mode 2 days). Intensive therapy unit admission was required in six patients for mechanical ventilation 0 to 3 days. Five patients (14%) had no improvement in symptoms. There were no deaths, no 30-day readmissions, and no long-term neuralgia in this series. CONCLUSIONS: We found minimal access VATS plication of the diaphragm to be feasible and safe, but no firm conclusions should be drawn from our limited resources. We report the feasibility of concomitant bilateral VATS plication of the diaphragm in two adults, and this was not previously reported in the adult population. There is a need for further good quality, prospective studies, and randomized controlled studies evaluating efficacy of VATS diaphragmatic plication.


Assuntos
Diafragma/cirurgia , Eventração Diafragmática/cirurgia , Paralisia Respiratória/cirurgia , Cirurgia Torácica Vídeoassistida/métodos , Adulto , Idoso , Eventração Diafragmática/etiologia , Eventração Diafragmática/fisiopatologia , Feminino , Volume Expiratório Forçado , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso Periférico/complicações , Nervo Frênico , Paralisia Respiratória/etiologia , Paralisia Respiratória/fisiopatologia , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
20.
Respir Physiol Neurobiol ; 246: 39-46, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28790008

RESUMO

Injury to nerves innervating respiratory muscles such as the diaphragm muscle results in significant respiratory compromise. Electromyography (EMG) and transdiaphragmatic pressure (Pdi) measurements reflect diaphragm activation and force generation. Immediately after unilateral diaphragm denervation (DNV), ventilatory behaviors can be accomplished without impairment, but Pdi generated during higher force non-ventilatory behaviors is significantly decreased. We hypothesized that 1) the initial reduction in Pdi during higher force behaviors after DNV is ameliorated after 14 days, and 2) changes in Pdi over time after DNV are associated with concordant changes in contralateral diaphragm EMG activity and ventilatory parameters. In adult male rats, the reduced Pdi during occlusion (∼40% immediately after DNV) was ameliorated to ∼20% reduction after 14 days. Contralateral diaphragm EMG activity did not significantly change immediately or 14days after DNV compared to the pre-injury baseline for any motor behavior. Taken together, these results suggest that over time after DNV compensatory changes in inspiratory related muscle activation may partially restore the ability to generate Pdi during higher force behaviors.


Assuntos
Lateralidade Funcional/fisiologia , Músculos Respiratórios/fisiopatologia , Paralisia Respiratória/patologia , Paralisia Respiratória/fisiopatologia , Animais , Modelos Animais de Doenças , Estimulação Elétrica , Eletromiografia , Masculino , Movimento/fisiologia , Denervação Muscular/métodos , Nervo Frênico , Pletismografia Total , Ratos , Ratos Sprague-Dawley , Paralisia Respiratória/etiologia , Fatores de Tempo
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