Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 201
Filtrar
2.
Rev Clin Esp (Barc) ; 223(10): 596-603, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37898356

RESUMO

BACKGROUND AND AIMS: The Organic Law Regulating Euthanasia (LORE, for its initials in Spanish) came into force in June 2021. This study aims to examine knowledge of the LORE among physicians licensed in Spain as well as their involvement with and the impact of the law. METHODS: This work is a descriptive, cross-sectional study conducted by means of a survey. Information was gathered through a self-administered questionnaire. RESULTS: The survey was answered by 1446 physicians licensed in Spain. The samples' demographic characteristics were as follows: 54.7% were women, the mean age was 52 ±â€¯14 years, and 66.0% worked in a hospital. Catalonia was the autonomous community with the most participants (44.6%). Regarding specialties, anesthesiology and resuscitation had the highest number of participants (21.9%), followed by family and community medicine (18.5%). The LORE was known in detail by 24.3% of physicians, 58.0% had a positive opinion of it, and 31.1% had direct experience with the euthanasia procedure. Practitioners working in the hospital setting perceived the law more favorably compared to those in the primary care setting (62.3% vs. 47.3%, p < 0.01). CONCLUSIONS: Most doctors did not have in-depth knowledge of the LORE, although a majority supported its existence, particularly those in hospital medicine. Most physicians who viewed the LORE negatively were male, older, and worked in primary care. A minority of physicians considered registering as conscientious objectors.


Assuntos
Anestesiologia , Eutanásia , Médicos , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Espanha , Estudos Transversais , Inquéritos e Questionários , Atitude do Pessoal de Saúde
5.
Rev Esp Anestesiol Reanim (Engl Ed) ; 70(5): 269-275, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37150439

RESUMO

BACKGROUND: Brain ultrasound allows measuring the cerebral flow velocity, brain midline shift and optic nerve sheath diameter. Literature is scarce in determining the feasibility to perioperatively perform these measurements altogether and the cerebrovascular behavior in patients scheduled for elective craniotomy. METHODS: We assessed bilateral cerebral flow velocities, composite index, brain midline shift and optic nerve sheath diameter by cerebral ultrasound in patients scheduled for elective craniotomy before anesthetic induction, at extubation, and at 6 and 24 h after. The aim was to assess the feasibility of brain ultrasound in patients for elective craniotomy and to describe the changes in cerebral flow velocities, brain midline shift and optic nerve sheath diameter from baseline values at different times in the postoperative period. RESULTS: Sixteen patients were included, of these two were excluded from analysis due to an inadequate sonographic window. There were no changes throughout the study regarding cerebral flow velocity, brain midline shift nor optic nerve sheath diameter assessments. All parameters were maintained in the physiological range without significant variations during the procedure. No perioperative complications were detected. CONCLUSIONS: The results of our study show the feasibility to perform a perioperative assessment of cerebral flow velocity, brain midline shift or optic nerve sheath diameter jointly and successfully to obtain additional information of baseline cerebral hemodynamics in patients scheduled for elective craniotomy and their postoperative changes during the first 24 h. Future studies with lager samples are needed to address the efficacy of cerebral ultrasound as a monitoring tool.


Assuntos
Encéfalo , Ultrassonografia Doppler Transcraniana , Humanos , Estudos de Viabilidade , Velocidade do Fluxo Sanguíneo , Craniotomia , Nervo Óptico/diagnóstico por imagem
7.
An Sist Sanit Navar ; 45(2)2022 Jun 30.
Artigo em Espanhol | MEDLINE | ID: mdl-35786702

RESUMO

The COVID-19 pandemic has required the use of new technologies to carry out rehabilitation sessions for COP D remotely. The aim of this systematic review was to analyse the available evidence on the efficacy of telerehabilitation in COPD patients. PubMed, WOS, PEDro and Cochrane databases were consulted. The systematic review included nine clinical trials, 55.5% of which display good methodological quality. The most commonly used rehabilitation methods were applications or software for real-time video-calls, visualisation of exercises and recording progress. TR was as effective as outpatient pulmonary rehabilitation, with greater benefits in functional capacity, self-efficacy, mental health, exacerbations and emergency care visits, offering a cost-effective option with high patient satisfaction. The small number of studies and the variety of rehabilitation methods examined limit the value of the evidence obtained.


Assuntos
COVID-19 , Doença Pulmonar Obstrutiva Crônica , Telerreabilitação , Humanos , Pandemias , Doença Pulmonar Obstrutiva Crônica/reabilitação , Qualidade de Vida
8.
Rev Esp Anestesiol Reanim (Engl Ed) ; 69(2): 109-113, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35168917

RESUMO

Adults patients with congenital heart disease increasingly present for non cardiac surgery. The anesthetic management this type of patients in neurosurgery requires a meticulous surgical anesthetic planning. The need for urgent intervention, with the presence of a congenital heart disease evolved to Eisenmenger syndrome, associated to a difficult airway, is a challenge for the anesthesiologist. The use of dexmedetomidine may be a valid alternative. We present the case of a patient with Down syndrome, and Eisenmenger syndrome who underwent drainage of brain abscess from the emergency department and was subsequently scheduled for reintervention. We compare the different anesthetic techniques used in both procedures, analyzing the implications they had on the main physiopathological alterations presented by the patient.


Assuntos
Anestésicos , Síndrome de Down , Complexo de Eisenmenger , Cardiopatias Congênitas , Neurocirurgia , Adulto , Síndrome de Down/complicações , Complexo de Eisenmenger/complicações , Complexo de Eisenmenger/cirurgia , Humanos
9.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-34565573

RESUMO

Adults patients with congenital heart disease increasingly present for non cardiac surgery. The anesthetic management this type of patients in neurosurgery requires a meticulous surgical anesthetic planning. The need for urgent intervention, with the presence of a congenital heart disease evolved to Eisenmenger Syndrome, associated to a difficult airway, is a challenge for the anesthesiologist. The use of dexmedetomidine may be a valid alternative. We present the case of a patient with Down syndrome, and Eisenmenger syndrome who underwent drainage of brain abscess from the emergency department and was subsequently scheduled for reintervention. We compare the different anesthetic techniques used in both procedures, analyzing the implications they had on the main physiopathological alterations presented by the patient.

10.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32561114

RESUMO

In 2017, the Neurosciences section of the Spanish Society of Anaesthesiology, Critical Care and Pain Therapy published a national survey on postoperative care and treatment circuits in neurosurgery. The survey showed that practices vary widely, depending on the centre, the anaesthesiologist and the pathology of the patient. There is currently no standard postoperative circuit for cranial neurosurgical procedures in Spanish hospitals, and there is sufficient evidence to show that not all patients undergoing elective craniotomy should be routinely admitted to a postsurgical critical care unit. The aim of this study is to perform a narrative review of postoperative circuits in elective craniotomy in order to standardise clinical practice in the light of published studies. For this purpose, we searched MEDLINE (PubMed) to retrieve studies published in the last ten years, up to November 2019, using the keywords neurosurgery and postoperative care, craniotomyand postoperative care.


Assuntos
Craniotomia , Procedimentos Cirúrgicos Eletivos , Procedimentos Neurocirúrgicos , Cuidados Pós-Operatórios , Algoritmos , Humanos
11.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32471791

RESUMO

The Airway Division of the Catalan Society of Anaesthesiology, Intensive Care and Pain Management (SCARTD) presents its latest guidelines for the evaluation and management of the difficult airway. This update includes the technical advances and changes observed in clinical practice since publication of the first edition of the guidelines in 2008. The recommendations were defined by a consensus of experts from the 19 participating hospitals, and were adapted from 5 recently published international guidelines following an in-depth analysis and systematic comparison of their recommendations. The final document was sent to the members of SCARTD for evaluation, and was reviewed by 11 independent experts. The recommendations, therefore, are supported by the latest scientific evidence and endorsed by professionals in the field. This edition develops the definition of the difficult airway, including all airway management techniques, and places emphasis on evaluating and classifying the airway into 3 categories according to the anticipated degree of difficulty and additional safety considerations in order to plan the management strategy. Pre-management planning, in terms of preparing patients and resources and optimising communication and interaction between all professionals involved, plays a pivotal role in all the scenarios addressed. The guidelines reflect the increased presence of video laryngoscopes and second-generation devices in our setting, and promotes their routine use in intubation and their prompt use in cases of unanticipated difficult airway. They also address the increased use of ultrasound imaging as an aid to evaluation and decision-making. New scenarios have also been included, such as the risk of bronchoaspiration and difficult extubation Finally, the document outlines the training and continuing professional development programmes required to guarantee effective and safe implementation of the guidelines.


Assuntos
Manuseio das Vias Aéreas/normas , Manuseio das Vias Aéreas/métodos , Anestesia , Cuidados Críticos , Árvores de Decisões , Humanos , Manejo da Dor
13.
Rev Esp Anestesiol Reanim (Engl Ed) ; 67(2): 90-98, 2020 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31761317

RESUMO

The aim of this narrative review is to confirm that acute pain after craniotomy is frequent and presents with moderate to severe intensity. We also highlight the importance of not only treating post-craniotomy pain, but also of preventing it in order to reduce the incidence of chronic pain. Physicians should be aware that conventional postoperative analgesics (non-steroidal anti-inflammatory, paracetamol, cyclooxygenase inhibitors 2, opioids) are not the only options available. Performing a scalp block prior to surgical incision or after surgery, the use of intraoperative dexmedetomidine, and the perioperative administration of pregabalin are just some alternatives that are gaining ground. The management of post-craniotomy pain should be based on perioperative multimodal analgesia in the framework of an "enhaced recovery after surgery" (ERAS) approach.


Assuntos
Dor Aguda/terapia , Craniotomia/efeitos adversos , Manejo da Dor/métodos , Dor Pós-Operatória/terapia , Analgesia por Acupuntura/métodos , Dor Aguda/prevenção & controle , Analgésicos não Narcóticos/uso terapêutico , Analgésicos Opioides/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Dor Crônica/prevenção & controle , Dexmedetomidina/uso terapêutico , Gabapentina/uso terapêutico , Cefaleia/classificação , Humanos , Medição da Dor/métodos , Dor Pós-Operatória/classificação , Dor Pós-Operatória/prevenção & controle , Fenitoína/uso terapêutico , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores
14.
Actas Urol Esp (Engl Ed) ; 44(2): 119-124, 2020 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31864774

RESUMO

INTRODUCTION: To present the first case of a concomitant robotic radical prostatectomy and a left robotic partial nephrectomy performed by a single-port approach using the SP® da Vinci surgical system (Intuitive Surgical, Sunnyvale CA, EE.UU.). PATIENT AND METHODS: A 66-year-old male diagnosed with localized prostate cancer and a left kidney renal mass incidentally found on computed tomography (CT) scan during prostate cancer evaluation. Procedures were performed using a single supra-umbilical 3cm incision, plus one additional laparoscopic port, utilizing a standard Gelpoint® (Applied Medical, Rancho Santa Margarita, CA, EE.UU.) and replicating the technique previously described for single-port transperitoneal radical prostatectomy and partial nephrectomy with the use of the SP® robotic platform. RESULTS: Total operative time was 256minutes (min) with a console time of 108min for radical prostatectomy, and 101min for the partial nephrectomy respectively, including a warm ischemia time of 26min. Estimated blood loss was 250cc. Blood transfusion was not needed. Final pathology for prostate was adenocarcinoma Gleason 7 (4+3) and for the kidney lesion was renal cell carcinoma. After two months of follow-up, PSA was undetectable and no complications or recurrence were detected. CONCLUSIONS: The single-port approach has advantages as easier surgical planning and transition for combined and multi-quadrants surgeries: faster recovery, minimal postoperative pain and need for opioids, and excellent cosmetic outcome. We suggest that combined procedures should be performed only in high volume institutions by surgeons with vast experience in robotic surgery in selected patients.


Assuntos
Adenocarcinoma/cirurgia , Carcinoma de Células Renais/cirurgia , Neoplasias Renais/cirurgia , Neoplasias Primárias Múltiplas/cirurgia , Nefrectomia/métodos , Prostatectomia/métodos , Neoplasias da Próstata/cirurgia , Procedimentos Cirúrgicos Robóticos , Idoso , Terapia Combinada , Humanos , Masculino
15.
Rev Esp Anestesiol Reanim (Engl Ed) ; 66(10): 497-505, 2019 Dec.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31759615

RESUMO

BACKGROUND: The diaphragm pacemaker (DP) has proven its utility in replacing mechanical ventilation in patients with chronic spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). The DP improves patient quality of life and reduces morbidity and mortality and their associated health care costs. The anesthetic management of these patients and the particularities of the surgical procedure are challenging. The aim of our study is to analyze anesthetic management and intraoperative complications in patients undergoing DP placement in our hospital. METHODS: We performed a chart review of patients treated between December 2007 and July 2017, recording the patients' preoperative status, anesthetic management and intraoperative complications. RESULTS: The study included 16 patients (5 pediatric) undergoing DP implantation for chronic SCI (63%), ALS (25%) and other neurologic conditions (12%). Abdominal laparoscopy was performed under general anesthesia, with intravenous (87%) or inhalational (13%) induction and maintenance using total intravenous (50%) or balanced (50%) anesthesia. Rocuronium was administered in one case to permit airway management. Complications included: hypotension (50%), difficulties in mechanical ventilation during laparoscopy (31%), pneumothorax (12.5%) and autonomic dysreflexia (6%). CONCLUSIONS: DP placement under general anesthesia is a safe intervention in both adult and pediatric patients. Complications derived from both the underlying disease and the surgical technique may appear, and must be rapidly identified and treated to obtain a satisfactory surgical outcome.


Assuntos
Esclerose Lateral Amiotrófica/complicações , Anestesia Geral/métodos , Diafragma , Marca-Passo Artificial , Quadriplegia/complicações , Transtornos Respiratórios/terapia , Traumatismos da Medula Espinal/complicações , Adolescente , Adulto , Idoso , Disreflexia Autonômica/etiologia , Criança , Pré-Escolar , Doença Crônica , Feminino , Humanos , Hipotensão/etiologia , Neuroestimuladores Implantáveis , Complicações Intraoperatórias/etiologia , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Nervo Frênico/lesões , Pneumotórax/etiologia , Transtornos Respiratórios/etiologia , Respiração Artificial/efeitos adversos , Estudos Retrospectivos , Traqueostomia/estatística & dados numéricos
16.
Transplant Proc ; 51(2): 311-313, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30879530

RESUMO

INTRODUCTION: We aimed to evaluate if ex vivo machine perfusion could minimize the negative impact of cold ischemia on those renal grafts obtained from controlled donation after circulatory death (cDCD). MATERIAL AND METHODS: Prospective observational paired study of kidney transplants from cDCD performed in our center. The kidney from each pair preserved on ice was transplanted first within the first few hours following procurement, while the contralateral kidney was machine-perfused with a LifePort device (Organ Recovery Systems, Brussels, Belgium) and transplanted the following day. RESULTS: A total of 12 cDCDs were included. No differences were observed in delayed graft dysfunction or graft survival between the 2 groups. CONCLUSION: The use of ex vivo perfusion devices is simple and they do not require any large infrastructural or high economic investments, considering the fact that it allows a better selection of recipients and viable organs no longer need to be discarded because of prolonged warm ischemia times.


Assuntos
Isquemia Fria/efeitos adversos , Criopreservação/métodos , Função Retardada do Enxerto/epidemiologia , Transplante de Rim/métodos , Perfusão/métodos , Bélgica , Feminino , Sobrevivência de Enxerto/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/métodos , Estudos Prospectivos
17.
Transplant Proc ; 51(2): 341-343, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30879537

RESUMO

BACKGROUND: Many studies demonstrate the relationship between the high intrapatient variability of calcineurin inhibitor (CNI) levels and poor long-term renal graft outcome. Our objective is to analyze the intrapatient variability observed in the mammalian target of rapamycin inhibitors (mTOR-i) blood levels, to compare the variability of sirolimus (SRL) with that of everolimus (EVL) in kidney transplant patients converted to an mTOR-i, and to analyze whether the coefficient of variation (CV) was correlated with long-term graft survival. METHODS: We analyzed 279 adult renal transplant patients converted to an mTOR-i. CV was calculated using at least 3 blood trough levels between 3 and 18 months postconversion. RESULTS: The mean and median CV of the entire group was 25.54% and 23.7%, respectively. SRL and EVL mean CV was 23.8% and 27.1% (P = .03), respectively. The group of patients into the last tertile with CV> 28.52% presented a lower death-censored graft survival (75.26% vs. 93.01%, P < .0001) with a mean follow-up of 66.5 months. CONCLUSION: The CV of mTOR-i is correlated with long-term renal graft survival, so it should be considered a prognostic factor. SRL has a lower CV than EVL in renal transplant patients converted to mTOR-i in the stable posttransplant phase.


Assuntos
Everolimo/uso terapêutico , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Sirolimo/uso terapêutico , Adulto , Inibidores de Calcineurina/sangue , Inibidores de Calcineurina/uso terapêutico , Everolimo/sangue , Feminino , Humanos , Imunossupressores/sangue , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Sirolimo/sangue
18.
J Intellect Disabil Res ; 63(8): 1041-1067, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30788876

RESUMO

BACKGROUND: Down syndrome is the most common chromosomal abnormality, with a worldwide incidence of around 0.1% in live births. It is related to several conditions in which the physical therapy could take action-preventing co-morbidities. This study aims to evaluate the effectiveness of physical therapy in Down syndrome, to know and compare the effectiveness of different physical therapy interventions in this population. METHODS: A systematic review and a meta-analysis of randomised controlled trials were conducted. The search was performed during June 2018 in the following databases: PubMed, Web of Science, Physiotherapy Evidence Database and Scopus. The studies were selected using predefined inclusion and exclusion criteria. The Physiotherapy Evidence Database scale evaluated the quality of the methods used in the studies. Subsequently, the data were extracted, and statistical analysis was performed when possible. RESULTS: A total of 27 articles were included, of which nine contributed information to the meta-analysis. Statistical analysis showed favourable results for the strength of upper and lower limbs [standardised mean difference (SMD) = 1.46; 95% confidence interval (CI): (0.77-2.15); and SMD = 2.04; 95% CI: (1.07-3.01)] and mediolateral oscillations of balance [SMD = -3.30; 95% CI: (-5.34 to -1.26)]. CONCLUSIONS: The results show the potential benefit of certain types of physical therapy interventions, specifically in strength and balance, in people with Down syndrome. There are still many aspects to clarify and new lines of research.


Assuntos
Síndrome de Down/reabilitação , Modalidades de Fisioterapia , Humanos
19.
Radiologia (Engl Ed) ; 61(2): 143-152, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30616862

RESUMO

PURPOSE: Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy. METHODS: Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.<8) and PMI (≥3vs.<3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate. RESULTS: CTASI pc-ASPECTS, dichotomized at <8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived. CONCLUSION: PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.


Assuntos
Angiografia por Tomografia Computadorizada , Procedimentos Endovasculares , Trombólise Mecânica , Insuficiência Vertebrobasilar/cirurgia , Idoso , Idoso de 80 Anos ou mais , Procedimentos Endovasculares/mortalidade , Feminino , Humanos , Masculino , Trombólise Mecânica/mortalidade , Pessoa de Meia-Idade , Seleção de Pacientes , Prognóstico , Estudos Retrospectivos , Tempo para o Tratamento , Resultado do Tratamento , Insuficiência Vertebrobasilar/diagnóstico por imagem , Insuficiência Vertebrobasilar/mortalidade
20.
Rev Esp Quimioter ; 31(6): 493-498, 2018 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-30421879

RESUMO

OBJECTIVE: To evaluate the utility of the granulocyte CD64 index as a marker of infection in patients with postoperative fever. METHODS: Prospective observational study of a cohort of patients with postoperative fever (2nd-21st day after the intervention) collected during 14 months. Obtaining blood samples during the first 24 hours after the febrile peak to determine the CD64 index (ratio of fluorescence intensity, measured, in the granulocytes of the patient with respect to healthy controls), procalcitonin and C-reactive protein (CRP). RESULTS: During the study period, 50 patients were included, 28 patients (56%) with infection and 22 patients (44%) without evidence of infection. The PCR, procalcitonin and the CD64 index showed significantly higher values in the group of patients who suffered infection. The CD64 index showed a sensitivity of 88.9%, with a specificity of 65.2%. The positive predictive value (PPV) was 75% and the negative predictive value (NPV) was 83.3%, with an area under the curve (AUC) of 0.805 (95% CI 0.68-0.93). Procalcitonin presented a sensitivity of 53.9% and specificity of 86.4%, with NPV and PPV of 82.4% and 61.3% respectively, with AUC of 0.752 (95% CI 0.61-0.89). Regarding the PCR, it showed a sensitivity of 100%, with specificity of 4.4% with an area under the curve of 0.676 (95% CI 0.52-0.83). CONCLUSIONS: The quantification of the CD64 index in patients who develop fever in the early postoperative period is useful to distinguish post-surgical inflammatory phenomena from episodes of established infection.


Assuntos
Biomarcadores/análise , Febre/diagnóstico , Febre/etiologia , Complicações Pós-Operatórias/diagnóstico , Receptores de IgG/análise , Infecção da Ferida Cirúrgica/diagnóstico , Adulto , Idoso , Proteína C-Reativa/análise , Feminino , Granulócitos/química , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/microbiologia , Valor Preditivo dos Testes , Pró-Calcitonina/análise , Estudos Prospectivos , Sensibilidade e Especificidade , Infecção da Ferida Cirúrgica/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA