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1.
Artigo em Inglês | MEDLINE | ID: mdl-38423462

RESUMO

The PENG block (pericapsular nerve group) is a recently described technique to address the innervation of the hip, one of the most complex anatomical regions to treat at the locoregional level. We present the case of a patient with acute lymphoblastic leukaemia complicated by avascular necrosis of the bilateral femoral head and previous history of severe chronic pain with probable central sensitization to opioids and a severe thrombocytopenia due to myelotoxicity from chemotherapy treatment. Given the need for orthopaedic surgery to manage femoral necrosis and in anticipation of complex perioperative pain management, a multimodal strategy was planned including bilateral ultrasound-guided continuous PENG blocks to achieve proper pain control in the perioperative period and promote early recovery. The operation and initial recovery were uneventful and the patient was discharged to the ward within 24 h and started early rehabilitation as planned. The patient had a successful recovery with good functionality.


Assuntos
Necrose da Cabeça do Fêmur , Bloqueio Nervoso , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Bloqueio Nervoso/métodos , Necrose da Cabeça do Fêmur/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Ultrassonografia de Intervenção , Masculino , Adulto , Trombocitopenia/induzido quimicamente , Anestésicos Locais/administração & dosagem
2.
Rev. esp. anestesiol. reanim ; 70(7): 395-398, Agos-Sept- 2023. ilus
Artigo em Espanhol | IBECS | ID: ibc-223997

RESUMO

El dolor abdominal crónico es una entidad muy prevalente en la población pediátrica y supone todo un reto diagnóstico para los profesionales, siendo frecuentemente infradiagnosticada. Requiere un abordaje multidisciplinar y una minuciosa evaluación clínica para descartar otras enfermedades. El ACNES consiste en un atrapamiento de los nervios cutáneos anteriores de los nervios intercostales y origina un dolor abdominal intenso, unilateral, circunscrito y frecuentemente presenta un Pinch test y un test de Carnett positivos. El planteamiento terapéutico debería contemplarse desde un enfoque gradual, reservando las técnicas más invasivas para los pacientes con ACNES refractario. Entre los múltiples tratamientos posibles las infiltraciones locales presentan una alta tasa de éxito, reservando las técnicas quirúrgicas para los casos refractarios. Presentamos el caso clínico de una niña de 11 años, con ACNES de 6 meses de evolución, con grave afectación de su calidad de vida y con respuesta favorable a la técnica de radiofrecuencia pulsada.(AU)


Chronic abdominal pain is a highly prevalent entity in the paediatric population and represents a diagnostic challenge for professionals. It is frequently underdiagnosed, and must be treated by a multidisciplinary team after a detailed clinical evaluation has been performed to rule out other pathologies. Anterior cutaneous nerve entrapment syndrome (ACNES) occurs when the anterior cutaneous abdominal nerves become pinched or trapped, causing intense, unilateral, circumscribed abdominal pain. Patients often present a positive Pinch test or Carnett's sign. A stepwise therapeutic approach should be used, reserving the most invasive techniques for patients with refractory ACNES. Among the many different treatments available, local anaesthesia infiltration has shown a high success rate, and surgery should only be performed in the most refractory cases. We report the case of an 11-year old girl with a 6-month history of ACNES that severely affected her quality of life, who responded well to pulsed radiofrequency ablation.(AU)


Assuntos
Humanos , Feminino , Criança , Tratamento por Radiofrequência Pulsada , Dor Abdominal/radioterapia , Manejo da Dor , Qualidade de Vida , Nervos Intercostais , Anestesiologia , Resultado do Tratamento , Pacientes Internados , Exame Físico , Avaliação de Sintomas
3.
Artigo em Inglês | MEDLINE | ID: mdl-36940851

RESUMO

Chronic abdominal pain is a highly prevalent entity in the paediatric population and represents a diagnostic challenge for professionals. It is frequently underdiagnosed, and must be treated by a multidisciplinary team after a detailed clinical evaluation has been performed to rule out other pathologies. Anterior cutaneous nerve entrapment syndrome (ACNES) occurs when the anterior cutaneous abdominal nerves become pinched or trapped, causing intense, unilateral, circumscribed abdominal pain. Patients often present a positive Pinch test or Carnett's sign. A stepwise therapeutic approach should be used, reserving the most invasive techniques for patients with refractory ACNES. Among the many different treatments available, local anaesthesia infiltration has shown a high success rate, and surgery should only be performed in the most refractory cases. We report the case of an 11-year old girl with a 6-month history of ACNES that severely affected her quality of life, who responded well to pulsed radiofrequency ablation.


Assuntos
Síndromes de Compressão Nervosa , Tratamento por Radiofrequência Pulsada , Humanos , Criança , Feminino , Qualidade de Vida , Tratamento por Radiofrequência Pulsada/efeitos adversos , Músculos Abdominais/inervação , Dor Abdominal/etiologia , Síndromes de Compressão Nervosa/diagnóstico , Síndromes de Compressão Nervosa/cirurgia
4.
Ginecol. obstet. Méx ; 86(1): 62-69, feb. 2018. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-975403

RESUMO

Resumen ANTECEDENTES: La afectación mamaria por un linfoma es poco frecuente; casi siempre se trata de linfomas tipo B que se caracterizan por falta de especificidad clínica y radiológica, lo que dificulta el diagnóstico diferencial con tumoraciones mamarias de otro origen. CASO CLÍNICO: Paciente de 72 años de edad, con antecedentes de hipercolesterolemia, hipertensión arterial, artrosis y depresión, con dos partos y menopausia a los 55 años. Madre con antecedente de cáncer de mama posmenopáusico. En la mamografía de la mama derecha se encontró una masa retroareolar de 8 cm, de contornos mal definidos y una adenopatía axilar con engrosamiento cortical. La biopsia reportó un linfoma no Hodgkin B de alto grado. Se administraron 8 ciclos de quimioterapia con el esquema R-CHOP. Luego de este esquema el PET-TC mostró una lesión mamaria derecha residual, metabólicamente inactiva, sin enfermedad nodal ni extramamaria supra ni infradiafragmática. CONCLUSIONES: Una neoplasia maligna mamaria no siempre se trata de un carcinoma ductal o lobulillar. Es necesario valorar la posibilidad de otras estirpes histológicas o, incluso, de una afectación metastásica. La entrevista y exploración adecuadas son fundamentales para una buena orientación diagnóstica.


Abstract BACKGROUND: The mammary affectation by a lymphoma is not frequent; it almost always involves type B lymphomas. It is characterized by a lack of clinical and radiological specificity, which makes differential diagnosis difficult with mammary tumors of another origin. CLINICAL CASE: A 72-year-old patient with a history of hypercholesterolemia, hypertension, osteoarthritis and depression, with two deliveries and menopause at 55 years of age. Mother with a history of postmenopausal breast cancer. The mammography of the right breast reported the existence of a retroareolar mass of 8 cm, of ill-defined contours and an axillary adenopathy with cortical thickening. The biopsy reported a high-grade non-Hodgkin B lymphoma. 8 cycles of chemotherapy were administered with the R-CHOP scheme. After this procedure, the PET-CT showed a residual, metabolically inactive right mammary lesion, with nodal or extramammary supra or infradiaphragmatic disease. CONCLUSIONS: A malignant mammary neoplasm is not always a ductal or lobular carcinoma. It is necessary to evaluate the possibility of other histological strains or, even, of a metastatic affectation. The adequate interview and exploration are fundamental for a good diagnostic orientation.

5.
Appl Radiat Isot ; 129: 28-34, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28802155

RESUMO

We present a methodology to obtain the energy distribution of the neutron flux of an experimental nuclear reactor, using multi-foil activation measurements and the Expectation Maximization unfolding algorithm, which is presented as an alternative to well known unfolding methods such as GRAVEL. Self-shielding flux corrections for energy bin groups were obtained using MCNP6 Monte Carlo simulations. We have made studies at the at the Dry Tube of RECH-1 obtaining fluxes of 1.5(4)×1013cm-2s-1 for the thermal neutron energy region, 1.9(5)×1012cm-2s-1 for the epithermal neutron energy region, and 4.3(11)×1011cm-2s-1 for the fast neutron energy region.

6.
Ginecol Obstet Mex ; 84(4): 265-9, 2016 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-27443103

RESUMO

BACKGROUND: Cyst of Nuck is an infrequent disease originated in the inadequate obliteration of the processus vaginalis during the embrionary life of the woman. Clinically usually appears as a slowly growth inguinal tumor, painless, smooth, soft, fluctuant and irreducible. Differential diagnosis must include inguinal hernia and other etiologies of inguinal tumor, for which echography is the main diagnostic test. Treatment consists on surgical extirpation and local reparation. It is exposed a case of a patient with cyst of Nuck clinically typical. CLINICAL CASE: It is made a review of clinical, diagnostic and therapeutic approach of this disease.


Assuntos
Cistos , Canal Inguinal , Cistos/diagnóstico , Cistos/etiologia , Cistos/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade
7.
Clín. investig. ginecol. obstet. (Ed. impr.) ; 36(2): 76-80, mar. 2009. ilus
Artigo em Espanhol | IBECS | ID: ibc-59416

RESUMO

El higroma, o linfangioma quístico, se debe a una anomalía del sistema linfático producida por la obstrucción del drenaje de los sacos linfáticos cervicales al sistema venoso yugular. Habitualmente se localiza en la región cervical posterior o posterolateral y contiene múltiples tabiques. Entre el 20 y el 40% de los casos se asocia a normalidad cromosómica; el resto de los casos se asocia a diversas aneuplodías o malformaciones. El diagnóstico diferencial incluye edema nucal, meningocele, encefalocele, teratoma cervical, seudomembranas, hemangioma y quiste placentario subcorial.Su incidencia es de uno cada 1.775 a 6.000 nacidos vivos. La tasa de aneuploidía asociada al linfangioma quístico diagnosticado prenatalmente es del 45 al 60% (principalmente síndrome de Turner y síndrome de Down). También se ha observado asociación a otros síndromes polimalformativos. El resultado fetal es incierto y varía según los estudios revisados.A continuación se presenta el caso de un linfangioma quístico inusual por varios motivos: su gran tamaño, la ausencia de otras anomalías morfológicas y de aneuploidías, la joven edad de la madre y el desarrollo morfológico posnatal normal (AU)


Hygroma or cystic lymphangioma is due to an obstruction of jugular lymph sac drainage to the jugular venous system. The most common localization is the posterolateral neck region. These lesions are usually multiseptated. Between 20% and 40% of affected individuals have a normal karyotype and the remainder show diverse aneuploidies and/or malformations. The differential diagnosis includes nuchal edema, meningocele, encephalocele, cervical teratoma, pseudomembranes, hemangioma and subchorial placental cyst.The incidence of cystic lymphangioma has been reported to be 1/6,000–1,775 live-newborns. The rate of aneuploidy associated with prenatally diagnosed cases are between 45% and 60% (mainly Turner and Down syndromes). Some cases are associated with other polymalformation syndromes. Fetal outcome is uncertain and differs among studies.We present the case of a fetal cystic lymphangioma that is unusual for several reasons: its huge size, the absence of any other morphological abnormalities and aneuploidies, the young age of the mother, and the normal morphological postnatal growth (AU)


Assuntos
Humanos , Feminino , Gravidez , Adulto , Linfangioma Cístico/diagnóstico , Linfangioma Cístico/cirurgia , Ultrassonografia Pré-Natal , Diagnóstico Pré-Natal
8.
Rev. esp. pediatr. (Ed. impr.) ; 61(5): 364-367, sept.-oct. 2005. tab
Artigo em Espanhol | IBECS | ID: ibc-60117

RESUMO

Objetivo: Determinar la eficacia de la restricción dietética en un grupo de niños y adolescentes con hipercolesterolemia. Diseño. Estudio prospectivo de intervención. Participantes. 265 niños y adolescentes de ambos sexos, con edades comprendidas entre los 2 y los 13 años diagnosticados de hipercolesterolemia. Todos ellos fueron tratados con restricción dietética mediante las dietas fase 1 o fase 2 de la Asociación Americana de Cardiología. El período de seguimiento osciló entre 5 y 15 años. Resultados. Los niveles de colesterol total, colesterol LDL, apolipoproteína B-100, apolipoproteína A y triglicéridos, descendieron significativamente (P<0,0001). El cociente colesterol LDL/colesterol HDL descendió significativamente. Conclusiones. El tratamiento dietético es efectivo en el tratamiento de la hipercolesterolemia en niños y adolescentes. La restricción dietética tiene un efecto beneficioso, no sólo en los niveles de colesterol total y LDL colesterol, sino también en los niveles de apolipoproteínas A-I y B-100 (AU)


Objective. To determine the effectiveness of dietary restriction in a group of children and adolescents with hypercholesterolemia. Research design. Intervention prospective study. Participants. Two hundred sixty-five children and adolescents of both sexes age 2 to 13 years diagnosed as having hypercholesterolemia. All to them were treated with dietary restriction (American Heart Association Step-One and Step Two Diets). The follow-up period ranged from 5 to 15 years. Results. Total cholesterol, low-density lipoprotein cholesterol, triglycerides and apolipoproteins A and B levels decreased significantly (p<0.0001). Low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio decreased significantly (p<0.0001). Conclusions. Diet therapy is effective in the treatment of hypercholesterolemia in children and adolescents. Dietary restriction has a beneficial effect not only on total cholesterol and low-density lipoprotein cholesterol levels but also on apolipoprotein A-I and B -100 levels (AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Dietoterapia , Hipercolesterolemia/dietoterapia , Hipercolesterolemia/diagnóstico , Arteriosclerose/complicações , Arteriosclerose/dietoterapia , Hipercolesterolemia/fisiopatologia , Estudos Prospectivos , Colesterol/análise , Triglicerídeos
9.
Anesth Analg ; 93(1): 53-5, TOC, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11429338

RESUMO

IMPLICATIONS: After administration of terlipressin to treat hypotension related to induction of general anesthesia, profound hypertension occurred in association with myocardial ischemia and occlusion of the left anterior descending coronary artery. The authors emphasize cautious use of this drug because of such adverse events.


Assuntos
Anti-Hipertensivos , Hipotensão/diagnóstico , Lipressina , Isquemia Miocárdica/diagnóstico , Pró-Fármacos , Anestesia Geral , Angioplastia Coronária com Balão , Aneurisma da Aorta Abdominal/cirurgia , Angiografia Coronária , Eletrocardiografia , Humanos , Hipotensão/fisiopatologia , Complicações Intraoperatórias/diagnóstico , Lipressina/análogos & derivados , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória , Isquemia Miocárdica/fisiopatologia , Terlipressina
10.
Perfusion ; 15(2): 105-10, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10789564

RESUMO

This study was designed to evaluate efficacy and tolerability of two different doses of aprotinin in patients receiving aspirin before undergoing coronary artery bypass grafting. Forty-two patients were randomized to receive either placebo (group I), or aprotinin in doses of 4,000,000 KIU (group II) or 6,000,000 KIU (group III). Drug efficacy was determined by measuring postoperative blood loss and transfusion of blood products. Both doses were effective in reducing blood loss and transfusion requirements. Blood loss through thoracotomy drainage was 450 +/- 224, 182 +/- 144, 142 +/- 98 ml, respectively, for control and treatment groups II and III (p = 0.0001). The numbers of patients with blood transfusions were seven (50%), two (17%) and two (17%) for group I and treatment groups II and III, respectively (p = 0.10). Tolerability was excellent and complications few and reversible. In conclusion, high and medium doses of aprotinin were well tolerated and reduced bleeding and transfusion requirements in patients submitted to coronary bypass surgery under the effects of aspirin.


Assuntos
Aprotinina/administração & dosagem , Aspirina/administração & dosagem , Perda Sanguínea Cirúrgica/prevenção & controle , Ponte Cardiopulmonar , Ponte de Artéria Coronária , Hemostáticos/administração & dosagem , Inibidores da Agregação Plaquetária/administração & dosagem , Pré-Medicação , Adulto , Idoso , Aprotinina/uso terapêutico , Aspirina/efeitos adversos , Aspirina/uso terapêutico , Transfusão de Sangue/estatística & dados numéricos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Drenagem , Feminino , Hemostáticos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/efeitos adversos , Inibidores da Agregação Plaquetária/uso terapêutico , Hemorragia Pós-Operatória/prevenção & controle , Período Pós-Operatório , Estudos Prospectivos , Segurança , Toracotomia , Resultado do Tratamento
11.
Rev Med Chil ; 127(1): 45-52, 1999 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-10436678

RESUMO

BACKGROUND: There is a growing interest to perform a left internal mammary artery (LIMA) graft to the left anterior descending coronary artery (LAD) on a beating heart through a minimally invasive access to the chest cavity. AIM: To report the experience with minimally invasive coronary artery surgery. PATIENTS AND METHODS: Analysis of 11 patients aged 48 to 79 years old with single vessel disease that, between 1996 and 1997, had a LIMA graft to the LAD performed through a minimally invasive left anterior mediastinotomy, without cardiopulmonary bypass. A 6 to 10 cm left parasternal incision was done. The LIMA to the LAD anastomosis was done after pharmacological heart rate and blood pressure control and a period of ischemic pre conditioning. Graft patency was confirmed intraoperatively by standard Doppler techniques. Patients were followed for a mean of 11.6 months (7-15 months). RESULTS: All patients were extubated in the operating room and transferred out of the intensive care unit on the next morning. Seven patients were discharged on the third postoperative day. Duplex scanning confirmed graft patency in all patients before discharge; in two patients, it was confirmed additionally by arteriography. There was no hospital mortality, no perioperative myocardial infarction and no bleeding problems. After follow up, ten patients were free of angina, in functional class I and pleased with the surgical and cosmetic results. One patient developed atypical angina on the seventh postoperative month and a selective arteriography confirmed stenosis of the anastomosis. A successful angioplasty of the original LAD lesion was carried out. CONCLUSIONS: A minimally invasive left anterior mediastinotomy is a good surgical access to perform a successful LIMA to LAD graft without cardiopulmonary bypass, allowing a shorter hospital stay and earlier postoperative recovery. However, a larger experience and a longer follow up is required to define its role in the treatment of coronary artery disease.


Assuntos
Doença das Coronárias/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Procedimentos Cirúrgicos Vasculares/métodos , Adulto , Idoso , Feminino , Seguimentos , Humanos , Anastomose de Artéria Torácica Interna-Coronária , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
12.
Rev Esp Anestesiol Reanim ; 45(9): 389-96, 1998 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-9847657

RESUMO

Various consensus groups convened in recent years to discuss plasma volume expansion solutions have suggested limiting the use of human albumin because of its high cost and have favored synthetic crystalloids or colloids for most clinical settings. Dextrans are colloids that are not widely used in most Europeans countries. Gelatins, in spite of the fact that unlimited amounts can be used, produce only moderate volume expansion and can trigger allergic reactions. The availability in Spain of hydroxyethylstarches (HES), a new type of colloid, may significantly change volume replacement strategy. HES are modified natural polymers. Three types, with different initial molecular weights, are used in Europe: high molecular weight HES, whose use in increasingly rare; low molecular weight HES (Expafusin), whose effect is short-lived; and medium molecular weight HES (Elohes, Fresenius-Laboratories Mein), which have recently been registered in Spain. Studies have shown that Elohes 6% (6% HES 200/0.62) provides volume expansion comparable to that of human albumin in clinical settings (cardiac surgery, shock, burns, etc.). The side effects of HES are usually minor. The frequency of anaphylactoid reactions is low, similar to that associated with human albumin. The effects on coagulation depend on molecular weight and duration of HES administration. Only in studies of hemodilution lasting 10 days with 6% HES 200/0.62 has VIII/von Willebrand complex been shown to decrease. If the recommended daily dose of this HES is respected, however, coagulation disorders are minimal. The effect of HES on kidney function is at present a subject of controversy. Thus, thanks to its prolonged effect on volume and few side effects, medium molecular weight HES colloids are the ones most often recommended for use in anesthesia and postoperative intensive care.


Assuntos
Derivados de Hidroxietil Amido , Substitutos do Plasma , Polímeros , Amido , Humanos , Derivados de Hidroxietil Amido/efeitos adversos , Derivados de Hidroxietil Amido/farmacocinética , Derivados de Hidroxietil Amido/farmacologia , Substitutos do Plasma/efeitos adversos , Substitutos do Plasma/farmacocinética , Substitutos do Plasma/farmacologia , Polímeros/efeitos adversos , Polímeros/farmacocinética , Polímeros/farmacologia , Albumina Sérica/uso terapêutico , Amido/efeitos adversos , Amido/farmacocinética , Amido/farmacologia
13.
Anesth Analg ; 86(1): 3-8, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9428842

RESUMO

UNLABELLED: We prospectively studied the effects of renal protection intervention in 17 patients with preoperative abnormal renal function (plasma creatinine > 1.5 mg/dL) scheduled for elective coronary surgery. Patients were randomized to either dopamine 2.0 micrograms.kg-1.min-1 (Group 1, n = 10) or perfusion pressure > 70 mm Hg during cardiopulmonary bypass (CPB) (Group 2, n = 7). Glomerular filtration rate and effective renal plasma flow were measured with inulin and 125I-hippuran clearances before the induction of anesthesia, after sternotomy and before CPB, during hypo- and normothermic CPB, after sternal closure, and 1 h postoperatively. Plasma and urine electrolytes were measured, and free water, osmolar, and creatinine clearances, as well as fractional excretion of sodium and potassium, were calculated before and after surgery. Significant differences between groups were found before CPB for glomerular filtration rate (higher in Group 1), urine output (2.0 vs 0.29 mL/min in Group 1 versus Group 2), urinary creatinine (66 vs 175 mg/dL), urinary osmolarity (370 vs 627 mOsm/L), osmolar clearance (2.1 vs 0.7 mL/min), and urinary potassium (33 vs 71 mEq/L). There were no differences between groups during hypo- and normothermic CPB. After CPB, the only difference was a slightly higher urinary creatinine in Group 2. Renal plasma flow was lower than normal in all patients before the induction of anesthesia. A nonsignificant trend toward increased flow was seen during hypothermic CPB. Filtration fraction was high before CPB, which suggests efferent arteriolar vasoconstriction, descending toward normal during and after CPB. The same pattern of changes was present in both groups. In conclusion, there were no clinically relevant differences between the two treatment modalities during and after CPB. However, significant differences were observed before CPB, when dopamine seemed to partially revert renal vasoconstriction. IMPLICATIONS: Two protective interventions were compared in patients undergoing heart surgery to prevent deterioration of renal function; these were dopamine infusion throughout the operation and phenylephrine infusion during cardiopulmonary bypass. We found clinically relevant differences only during surgery before cardiopulmonary bypass.


Assuntos
Ponte Cardiopulmonar , Dopamina/farmacologia , Rim/fisiopatologia , Fenilefrina/farmacologia , Insuficiência Renal/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/efeitos dos fármacos , Feminino , Humanos , Rim/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
14.
Anesth Analg ; 84(5): 958-63, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9141915

RESUMO

We determined the arterial pressure-flow relationship experimentally by means of step changes of blood flow in 30 adult patients undergoing cardiopulmonary bypass (CPB). Anesthesia technique was uniform. CPB was nonpulsatile; hypothermia to 25-28 degrees C, and hemodilution to 18%-25% hematocrit were used. During stable bypass, mean arterial pressure was recorded first with blood flow 2.2 L.min-1.m-2. Flow was then increased to 2.9 L.min-1.m-2 for 10 s and reverted to baseline for 1 min. Then it was decreased to 1.45 L.min-1.m-2 for 10 s, and reverted to baseline for 1 min. Subsequently, it was decreased to 0.73 L.min-1.m-2 for 10 s and then reverted to baseline. Similar sets of measurements were repeated after 0.25 mg of phenylephrine and once the patient was rewarmed. The pressure-flow function was individually determined by regression, and the critical pressure estimated by extrapolation to zero flow. All patients had zero-flow critical pressure during hypothermia, with a mean value of 21.8 +/- 6.4 mm Hg (range 8.8-38.9). It increased after 0.25 mg phenylephrine to 25.4 +/- 7.2 mm Hg (range 12.2-43.9, P < 0.001). During normothermia, critical pressure was 21.2 +/- 5 mm Hg (range 13.4-30.9), not significantly different from hypothermia. During hypothermia, the slope of the pressure-flow function (i.e., resistance) was 14.9 +/- 3.5 mm Hg.L-1.min-1.m-2 (range 7.6-22.1). It increased significantly (P < 0.001) after phenylephrine, to 19.7 +/- 6.2 mm Hg.L-1.min-1.m-2 (range 11.4-40.5), and returned to 15.4 +/- 3.4 mm Hg.L-1.min-1.m-2 (range 10.1-24.2) during normothermic bypass. Systemic vascular resistance appeared to vary reciprocally with blood flow, although this finding may represent a mathematical artifact, which can be avoided by using zero-flow critical pressure in the vascular resistance equation.


Assuntos
Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Ponte Cardiopulmonar , Adulto , Idoso , Procedimentos Cirúrgicos Cardíacos , Feminino , Humanos , Hipotermia Induzida , Masculino , Pessoa de Meia-Idade , Resistência Vascular
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