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1.
Paediatr Anaesth ; 13(6): 541-9, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12846714

RESUMO

Digoxin-immune antibody fragments (Fab) for treatment of digitalis intoxication was introduced in 1976. Many reports have been published concerning this therapy for children, but few have focused on its immediate reversal of cardiac as well as extracardiac life-threatening manifestations of digoxin toxicity. We present a case of life-threatening digitalis intoxication in a child with postoperative renal insufficiency, after a Sennings procedure for transposition of the great arteries. Digoxin administration according to the nationally recommended dosage and intervals unexpectedly resulted in serum levels in the toxic range. Severe cardiac arrhythmias, haemodynamic instability and a rapid-increasing serum potassium level resulted. This report demonstrates how administration of Fab according to the manufacturer's dosage recommendation reversed the tachyarrhythmia immediately and re-established a normal level of serum potassium within minutes.


Assuntos
Anticorpos Bloqueadores/uso terapêutico , Cardiotônicos/efeitos adversos , Cardiotônicos/antagonistas & inibidores , Digoxina/efeitos adversos , Digoxina/antagonistas & inibidores , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Complicações Pós-Operatórias/induzido quimicamente , Complicações Pós-Operatórias/tratamento farmacológico , Especificidade de Anticorpos , Procedimentos Cirúrgicos Cardíacos , Cardiotônicos/imunologia , Digoxina/imunologia , Eletrocardiografia , Feminino , Humanos , Hiperpotassemia/tratamento farmacológico , Hiperpotassemia/etiologia , Lactente , Potássio/sangue , Transposição dos Grandes Vasos/cirurgia
2.
Lab Anim ; 36(3): 344-50, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12144744

RESUMO

Based on measurements of the circulating red blood cell volume (V(RBC)) in seven anaesthetized piglets using carbon monoxide (CO) as a label, plasma volume (PV) was calculated for each animal. The increase in carboxyhaemoglobin (COHb) concentration following administration of a known amount of CO into a closed circuit re-breathing system was determined by diode-array spectrophotometry. Simultaneously measured haematocrit (HCT) and haemoglobin (Hb) values were used for PV calculation. The PV values were compared with simultaneously measured PVs determined using the Evans blue technique. Mean values (SD) for PV were 1708.6 (287.3)ml and 1738.7 (412.4)ml with the CO method and the Evans blue technique, respectively. Comparison of PVs determined with the two techniques demonstrated good correlation (r = 0.995). The mean difference between PV measurements was -29.9 ml and the limits of agreement (mean difference +/-2SD) were -289.1 ml and 229.3 ml. In conclusion, the CO method can be applied easily under general anaesthesia and controlled ventilation with a simple administration system. The agreement between the compared methods was satisfactory. Plasma volume determined with the CO method is safe, accurate and has no signs of major side effects.


Assuntos
Monóxido de Carbono , Volume Plasmático/veterinária , Suínos/fisiologia , Administração por Inalação , Anestesia Geral , Animais , Determinação do Volume Sanguíneo/métodos , Determinação do Volume Sanguíneo/veterinária , Monóxido de Carbono/administração & dosagem , Carboxihemoglobina/metabolismo , Azul Evans/administração & dosagem , Hematócrito , Hemoglobinas/análise , Injeções Intravenosas , Volume Plasmático/fisiologia , Reprodutibilidade dos Testes , Espectrofotometria/instrumentação , Fatores de Tempo
3.
Acta Anaesthesiol Scand ; 46(1): 51-6, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11903072

RESUMO

BACKGROUND: Cardiopulmonary bypass (CPB) as used for cardiac surgery and for rewarming individuals suffering deep accidental hypothermia is held responsible for changes in microvascular fluid exchange often leading to edema and organ dysfunction. The purpose of this work is to improve our understanding of fluid pathophysiology and to explore the implications of the changes in determinants of transcapillary fluid exchange during CPB with and without hypothermia. This investigation might give indications on where to focus attention to reduce fluid extravasation during CPB. METHODS: Published data on "Starling variables" as well as reported changes in fluid extravasation, tissue fluid contents and lymph flow were analyzed together with assumed/estimated values for variables not measured. The analysis was based on the Starling hypothesis where the transcapillary fluid filtration rate is given by: JV=Kf [Pc-Pi-sigma(COPp-COPi)]. Here Kf is the capillary filtration coefficient, sigma the reflection coefficient, P and COP are hydrostatic and colloid osmotic pressures, and subscript 'c' refers to capillary, 'i' to the interstitium and 'p' to plasma. RESULTS AND CONCLUSION: The analysis indicates that attempts to limit fluid extravasation during normothermic CPB should address primarily changes in Kf, while changes in both Kf and Pc must be considered during hypothermic CPB.


Assuntos
Permeabilidade Capilar/fisiologia , Ponte Cardiopulmonar , Temperatura , Animais , Síndrome de Vazamento Capilar/etiologia , Síndrome de Vazamento Capilar/fisiopatologia , Ponte Cardiopulmonar/efeitos adversos , Espaço Extracelular/fisiologia , Pressão Hidrostática , Hipotermia Induzida , Linfa/fisiologia , Pressão Osmótica , Suínos , Equilíbrio Hidroeletrolítico/fisiologia
4.
Acta Anaesthesiol Scand ; 45(6): 720-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11421830

RESUMO

BACKGROUND: Hypothermia, commonly used for organ protection during cardiopulmonary bypass (CPB), has been associated with changes in plasma volume, hemoconcentration and microvascular fluid shifts. Fluid pathophysiology secondary to hypothermia and the mechanisms behind these changes are still largely unknown. In a recent study we found increased fluid needs during hypothermic compared to normothermic CPB. The aim of the present study was to characterize the distribution of the fluid given to maintain normovolemia. In addition, we wanted to investigate the quantity and quality of the fluid extravasated during hypothermic compared to normothermic CPB. METHODS: Two groups of anesthetized piglets were studied during 2 h of hypothermic (28 degrees C) (n=7) or normothermic (38 degrees C) (n=7) CPB. Net fluid balance (input-output) was recorded. Changes in colloid osmotic pressures of plasma (COPp) and interstitial fluid (COPi), plasma volume (PV), hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), s-osmolality, s-albumin and s-total protein was followed throughout the experiments. Fluid extravasation rate was calculated. In addition, total tissue water content was measured and compared with a control group (n=6) (no CPB). RESULTS: During hypothermic compared with normothermic CPB, the average net positive fluid balance from 10-120 min of extracorporeal circulation was 1.35+/-0.06 ml x kg(-1) x min(-1) and 0.33+/-0.03 ml x kg(-1) x min(-1) respectively (P<0.0001). We found a marked increase in fluid extravasation during hypothermic CPB. The extravasation rate during hypothermia was 1.8+/-0.2 ml x kg(-1) x min(-1), (1st hour) and 1.1+/-0.2 ml x kg(-1) x min(-1) (2nd hour) compared with 0.8+/-0.2 ml x kg(-1) x min(-1), and 0.1+/-(0.1) ml x kg(-1) x min(-1) during normothermia, respectively (P<0.01). The total intravascular protein and albumin masses remained constant in both groups. Following hypothermic CPB, the water content increased significantly in all tissues and organs. CONCLUSION: During hypothermic CPB an increased extravasation of fluid from the intravascular to the interstitial space was found. As no leakage of proteins could be demonstrated, based on stable values for albumin and protein masses throughout the experiments, the extravasated fluid contained mainly water and small solutes.


Assuntos
Permeabilidade Capilar/fisiologia , Ponte Cardiopulmonar/efeitos adversos , Hipotermia Induzida/efeitos adversos , Albuminas/metabolismo , Animais , Volume Sanguíneo/fisiologia , Água Corporal/metabolismo , Monóxido de Carbono/sangue , Hemodinâmica/fisiologia , Masculino , Suínos , Termodiluição
5.
Eur J Cardiothorac Surg ; 20(1): 58-64, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11423275

RESUMO

OBJECTIVE: Twenty-six patients with accidental hypothermia combined with circulatory arrest or severe circulatory failure were rewarmed to normothermia by use of extracorporeal circulation (ECC). The aim of the present study was to evaluate our results. PATIENTS AND METHODS: The treatment of six female and 20 male patients (median age: 26.7 years; range 1.9--76.3 years) rewarmed in the period 1987--2000 was evaluated retrospectively. Hypothermia was related to immersion/submersion in cold water (n=17), avalanche (n=1) or prolonged exposure to cold surroundings (n=8). Prior to admission, the trachea was intubated and cardiopulmonary resuscitation (CPR) initiated in all patients with cardiorespiratory arrest (n=22), whereas in those with respiration/circulation (n=4) only oxygen therapy via a face mask was given. RESULTS: Nineteen of the 26 patients were weaned off ECC whereas seven died because of refractory respiratory and/or cardiac failure. Eight of the 19 successfully weaned patients were discharged from hospital after a median of 10 days. One patient died 3 days after circulatory arrest (complete atrioventricular block) resulting in severe cerebral injury. The remaining ten patients died following 1--2 days due to severe hypoxic brain injury (n=5), cerebral bleeding (n=1) or irreversible cardiopulmonary insufficiency (n=4). Based on the reports from the site of accident, two groups of patients were identified: the asphyxia group (n=15) (submersions (n=14); avalanche accident (n=1)) and the non-asphyxia group (n=11) (patients immersed or exposed to cold environment). Seven intact survivors discharged from hospital belonged to the non-asphyxia group whereas one with a severe neurological deficit was identified within the asphyxia group. CONCLUSION: Patients with non-asphyxiated deep accidental hypothermia have a reasonable prognosis and should be rewarmed before further therapeutic decisions are made. In contrast, drowned patients with secondary hypothermia have a very poor prognosis. The treatment protocol under such conditions should be the subject for further discussion.


Assuntos
Circulação Extracorpórea , Hipotermia/terapia , Reaquecimento/métodos , Adulto , Feminino , Humanos , Hipotermia/epidemiologia , Hipotermia/etiologia , Hipotermia/mortalidade , Imersão , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do Tratamento
6.
Acta Anaesthesiol Scand ; 44(10): 1220-5, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11065201

RESUMO

BACKGROUND: Edema, generalized overhydration and organ dysfunction commonly occur in patients undergoing open-heart surgery using cardiopulmonary bypass (CPB) and induced hypothermia. Activation of inflammatory reactions induced by contact between blood and foreign surfaces are commonly held responsible for the disturbances of fluid balance ("capillary leak syndrome"). We used an online technique to determine fluid shifts between the intravascular and the interstitial space during normothermic and hypothermic CPB. METHODS: Piglets were placed on CPB (fixed pump flow) via thoracotomy in general anesthesia. In the normothermic group (n=7), the core temperature was kept at 38 degrees C prior to and during 2 h on CPB, whereas in the hypothermic group (n=7) temperature was lowered to 28 degrees C during bypass. The CPB circuit was primed with acetated Ringer's solution. The blood level in the CPB circuit reservoir was held constant during bypass. Ringer's solution was added when fluid substitution was needed (falling blood level in the reservoir). In addition to invasive hemodynamic monitoring, fluid input and losses were accurately recorded. Inflammatory mediators or markers were not measured in this study. RESULTS: Cardiac output, s-electrolytes and arterial blood gases were similar in the two groups in the pre-bypass period. At start of CPB the blood level in the machine reservoir fell markedly in both groups, necessitating fluid supplementation and leading to a markedly reduced hematocrit. This extra fluid need was transient in the normothermic group, but persisted in the hypothermic animals. After 2 h of CPB the hypothermic animals had received 7 times more fluid as compared to the normothermic pigs. CONCLUSION: We found strong indications for a greater fluid extravasation during hypothermic CPB compared with normothermic CPB. The experimental model using the CPB-circuit reservoir as a fluid gauge gives us the opportunity to study further fluid volume shifts, its causes and potential ways to optimize fluid therapy protocols.


Assuntos
Ponte Cardiopulmonar , Equilíbrio Hidroeletrolítico , Animais , Hemodiluição , Hemodinâmica , Masculino , Suínos
7.
Tidsskr Nor Laegeforen ; 120(16): 1854-7, 2000 Jun 20.
Artigo em Norueguês | MEDLINE | ID: mdl-10925611

RESUMO

BACKGROUND: Different techniques have been used for treatment of victims with accidental hypothermia. We have used cardiopulmonary bypass (CPB) for rewarming hypothermic patients with circulatory failure or cardiac arrest. This report summarises our experiences with this patient group. MATERIAL AND METHODS: 23 patients, submersions (n = 15), avalanche (n = 1) and primary hypothermia (immersion/air cooling) (n = 7), were rewarmed using extracorporeal circulation with standard equipment for open-heart surgery. RESULTS: On a clinical basis, two patient populations could be identified; one group for whom asphyxia was probably present prior to and during cooling, and another group for whom asphyxia was unlikely. In the first group, one of 13 patients survived compared to the latter group where six out of ten survived. A search for laboratory and other variables that with certainty could contribute to the prediction of prognosis was unsuccessful. INTERPRETATION: Due to lack of safe prognostic predictors, all accidental hypothermic victims with circulatory failure should be rewarmed by cardiopulmonary bypass before further therapeutic decisions are made.


Assuntos
Circulação Extracorpórea , Máquina Coração-Pulmão , Hipotermia/terapia , Reaquecimento/métodos , Acidentes , Adolescente , Adulto , Idoso , Ponte Cardiopulmonar , Pré-Escolar , Emergências , Feminino , Humanos , Hipotermia/etiologia , Hipotermia/mortalidade , Hipotermia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico
8.
Lab Anim ; 32(4): 439-45, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9807758

RESUMO

The wick method for sampling of interstitial fluid from subcutis was applied in fluid balance studies in young pigs. Colloid osmotic pressure was measured in serum (COPs) and interstitial fluid (COPi) using a membrane colloid osmometer. Our aims were to determine the 'true' COPi, and to find the optimal duration of wick implantation. In series I (n = 6) a 'crossover' experiment was performed using wicks soaked in different priming solutions (non-diluted and diluted serum protein solutions or isotonic salt solution). Circulatory arrest was induced just before wick insertion in order to eliminate the vascular part of the acute inflammation. In series II (n = 6) wicks were removed in sequence after 60, 90, 120 and 180 min sampling time in anaesthetized pigs in vivo. COPs, COPi and haematocrit (HCT) together with haemoglobin (Hgb), serum albumin and total protein concentrations were determined in the same animals. In series I average COPs and COPi were 13.7 (1.4) and 7.2 (1.4) mmHg respectively (SD). In series II the optimal wick implantation times were estimated to be 60-90 min for wicks soaked in diluted protein solution, and 90-120 min for dry and saline-soaked wicks. COPs averaged 13.0 (0.7) mmHg, HCT 30.0 (1.6)%, Hgb 8.3 (0.9) g/dl, s-albumin 22.7 (0.6) g/l and s-protein 47.3 (2.3) g/l. Compared to commonly reported reference values, we found surprisingly low values for most of the measured variables. This may be related to the fact that we used immature pigs. An analysis of the validity of the wick method based on our own results and published reports is presented. We conclude that sampling of interstitial fluid with subcutaneous wicks is easy to perform in young pigs. However, the COP-values measured in wick fluid have to be carefully evaluated especially when sampling is performed in vivo.


Assuntos
Espaço Extracelular , Manejo de Espécimes/métodos , Anestesia , Animais , Estudos de Avaliação como Assunto , Pressão Osmótica , Manejo de Espécimes/normas , Suínos
9.
Lab Anim ; 32(3): 316-23, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9718480

RESUMO

The domestic pig is a useful model in certain areas of biomedical research. Effective use of this species is often encumbered by lack of reference values in conscious as well as anaesthetized animals. Anaesthesia itself influences physiological and biological variables; the anaesthetic technique often affects experimental results. The relationship between anaesthesia and haemodynamics is well characterized in man, but less established in pigs. We studied the effect of midazolam-fentanyl-isoflurane anaesthesia in six immature, male, domestic pigs (Norwegian landrace). Haemodynamic variables (heart rate, arterial systolic, mean, diastolic pressures, pulmonary systolic, mean, diastolic pressures, pulmonary capillary wedge pressure), tissue perfusion, lymph flow (thoracic duct) were recorded for 3 h in animals with open chest through midline sternotomy. Variables relevant to fluid balance, e.g. interstitial hydrostatic pressure (Pi), serum-colloid osmotic pressure (s-COP) and serum-albumin (s-albumin) and -protein (s-protein) concentrations were measured. With the chosen anaesthetic technique haemodynamic variables, including lymph flow, and laboratory variables remained constant during the study period. Most variables were similar to conditions in humans. In contrast to adult humans exposed to the same anaesthetic technique, these pigs had lower haemoglobin-, s-albumin- and s-protein concentrations. A finding which may reflect immaturity. Liver and lung perfusion decreased significantly during the study period whereas perfusion of the other organs studied remained constant. Lack of responses to defined noxious stimuli during the study period suggest adequate analgesia. We conclude that midazolam, fentanyl and isoflurane provide cardiovascular stability including normal microvascular fluid exchange, which are essential elements for securing the quality of results obtained during cardiovascular research in anaesthetized pigs.


Assuntos
Anestesia/veterinária , Fentanila/administração & dosagem , Hemodinâmica/efeitos dos fármacos , Isoflurano/administração & dosagem , Midazolam/administração & dosagem , Suínos/fisiologia , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Resistência Capilar , Frequência Cardíaca/efeitos dos fármacos , Hemoglobinas/análise , Masculino , Pressão Osmótica/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Suínos/sangue
10.
Acta Anaesthesiol Scand ; 42(2): 264-6, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9509214

RESUMO

A woman developed pulmonary embolism with cardiac arrest after caesarean section. Cardiopulmonary resuscitation was performed for 45 min during which echocardiography showed right ventricular dilatation. After stabilization, but still in a critical condition, the patient was transferred by airambulance to a hospital with facilities for extracorporeal circulation. A massive embolus was removed. Some hours after extubation the patient developed respiratory insufficiency and hypovolaemia. Re-intubation was followed by severe hypotension requiring external cardiac compression for about 15 min. An emergency explorative laparotomy revealed a ruptured liver with a subcapsular haematoma. A critical illness polyneuropathy made prolonged ventilatory support necessary. She recovered without cerebral sequelae.


Assuntos
Cesárea/efeitos adversos , Embolectomia , Parada Cardíaca/etiologia , Embolia Pulmonar/complicações , Adulto , Feminino , Humanos , Gravidez , Embolia Pulmonar/cirurgia , Ressuscitação
11.
Eur J Pharmacol ; 331(2-3): 259-66, 1997 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-9274988

RESUMO

The new anti-inflammatory agent alpha-trinositol (D-myo-inositol-1,2,6-trisphosphate), is suggested to act on the cellular adhesion receptor towards extracellular matrix components, the beta1-integrins, and may therefore represent a novel principle for therapy of the phenomena associated with acute inflammation. Increased negativity of interstitial fluid pressure (p(if)) is a major driving force for the rapid edema formation in trachea and skin associated with dextran anaphylaxis in the rat. We therefore used this experimental model to study the effect of alpha-trinositol in skin and trachea of pentobarbital anesthetized rats. p(if) was measured with sharpened glass capillaries (3-7 microm) connected to a servocontrolled counterpressure system. alpha-Trinositol (10 mg) was given before or after dextran. Circulatory arrest was induced 2 min after i.v. dextran to limit the increased capillary fluid filtration associated with the anaphylactic reaction. This increased filtration will otherwise raise interstitial volume and thereby p(if) and cause an underestimation of a potential increased negativity of p(if). In the trachea, p(if) was 0.0 +/- 1.0 mmHg (S.D.) and -1.4 +/- 0.5 mmHg in controls given saline vehicle and alpha-trinositol (P > 0.05), respectively, and fell to -8.5 +/- 2.7 mmHg after dextran (P < 0.01). alpha-Trinositol given 2 min prior to or after dextran resulted in p(if) of -1.7 +/- 1.2 mmHg (P > 0.05 versus control, P < 0.01 versus dextran) and -4.7 +/- 3.0 mmHg (P < 0.01 versus control and dextran), respectively. In skin, i.v. dextran caused p(if) to fall from -0.6 +/- 0.5 to -4.6 +/- 1.9 mmHg (P < 0.001). When alpha-trinositol was given prior to dextran the corresponding figures were -0.4 +/- 0.8 and -0.9 +/- 1.1 mmHg, respectively (P > 0.05). Subdermal administration of alpha-trinositol after i.v. dextran and circulatory arrest normalized p(if) in concentration of 100, 10 and partly at 1 mg/ml. Thus, alpha-trinositol prevented the increased negativity of p(if) induced by dextran anaphylaxis when administered prior to as well as after dextran showing that the alpha-trinositol also could influence an already started inflammatory reaction.


Assuntos
Anafilaxia/prevenção & controle , Anafilaxia/fisiopatologia , Anti-Inflamatórios não Esteroides/farmacologia , Dextranos , Espaço Extracelular/fisiologia , Fosfatos de Inositol/farmacologia , Anafilaxia/induzido quimicamente , Animais , Líquidos Corporais/fisiologia , Permeabilidade Capilar/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Feminino , Injeções Intravenosas , Cloreto de Potássio/farmacologia , Pressão , Ratos , Ratos Wistar , Pele/patologia , Pele/fisiopatologia , Traqueia/patologia , Traqueia/fisiopatologia
12.
Ultrasound Med Biol ; 23(2): 177-85, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9140176

RESUMO

UNLABELLED: The accuracy of cardiac output measurement by pulsed Doppler echocardiography can be affected by several factors, such as the velocity distribution, the measurement of diameter and the method of tracing the pulsed Doppler flow spectrum. This experimental study was designed to find the most accurate way of measuring cardiac output in consideration of all these factors. In 10 open-chest normal piglets (24 +/- 1 kg), the velocity distribution in the aortic annulus was evaluated using Doppler colour flow mapping. Cardiac output was measured by pulsed Doppler echocardiography in the aortic annulus by a number of different ways and compared to the simultaneous result of the thermodilution method. All measurements were made at baseline, after intravenous injection of esmolol and during infusion of dobutamine. RESULTS: (1) the velocity distribution in the aortic annulus in the piglets was just slightly skewed during all three haemodynamic situations; (2) The in vivo measurements of the diameter of the aortic annulus varied throughout the ejection period, but the average of the three largest diameter measurements was almost identical with the diameter measured in vitro (18.5 +/- 0.3 mm vs. 18.6 +/- 0.2 mm; p = NS); (3) Tracing the maximal velocity of the pulsed Doppler flow spectrum produced a cardiac output that was 18%-21% higher than that measured by the thermodilution method, while tracing the brightest part (modal velocity) of the pulsed Doppler flow spectrum yielded a cardiac output very close to the thermodilution measurement. CONCLUSION: The velocity distribution in the aortic annulus in the piglet has little effect on cardiac output measurement by pulsed Doppler. Using the maximal measurable diameter of the aortic annulus and tracing the brightest part of the pulsed Doppler flow spectrum yielded the cardiac output closest to that measured by the thermodilution method.


Assuntos
Valva Aórtica/diagnóstico por imagem , Velocidade do Fluxo Sanguíneo , Débito Cardíaco , Antagonistas Adrenérgicos beta/farmacologia , Animais , Valva Aórtica/fisiologia , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Cardiotônicos/farmacologia , Dobutamina/farmacologia , Ecocardiografia Doppler em Cores , Ecocardiografia Doppler de Pulso , Frequência Cardíaca/efeitos dos fármacos , Propanolaminas/farmacologia , Reprodutibilidade dos Testes , Suínos , Termodiluição
13.
Clin Physiol ; 15(6): 597-610, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8590554

RESUMO

An experimental study in 10 open chest normal pigs (body weight: 24 +/- 1 kg) was carried out to explore the relationship between the velocity distribution in the aortic annulus and the pattern of flow convergence in the left ventricular outflow tract. The cross-sectional velocity profiles in the aortic annulus were constructed by using Doppler colour flow mapping with a previously validated time-interpolation method. The pattern of flow convergence in the left ventricular outflow tract was quantified by measuring the colour flow areas on the anterior and posterior sides of the central axis of the aortic annulus, and calculating their difference. The dynamic changes of the velocity distribution, the pattern of flow convergence and the septal angle throughout systole were observed. The velocity distribution in the aortic annulus changed according to the pattern of flow convergence in the left ventricular outflow tract. During early systole, the pattern of flow convergence was most asymmetrical. With the central longitudinal axis of the aortic annulus as a reference, the main part of the converging flow was along the anterior wall of the left ventricular outflow tract. Consequently, the velocity profile in the aortic annulus was most skewed during the early systole, with the highest velocity along the anterior wall. Towards late systole, the pattern of flow convergence became more and more symmetrical, and the velocity distribution in the aortic annulus gradually became flat. A significant correlation was found between the extent of asymmetry of the pattern of flow convergence in the left ventricular outflow tract and the extent of skewness of the velocity distribution in the aortic annulus (r = 0.69, P < 0.001). Throughout systole, septal angle increased very slightly (from 35 +/- 3 to 38 +/- 3 degrees, P < 0.01). The pattern of flow convergence in the left ventricular outflow tract is a major determinant of the velocity distribution in the aortic annulus in pigs.


Assuntos
Aorta/fisiologia , Coração/fisiologia , Sístole/fisiologia , Função Ventricular Esquerda/fisiologia , Animais , Aorta/anatomia & histologia , Pressão Sanguínea/fisiologia , Ecocardiografia , Ecocardiografia Doppler em Cores , Eletrocardiografia , Coração/anatomia & histologia , Frequência Cardíaca/fisiologia , Suínos
14.
Circ Res ; 73(5): 839-45, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7691430

RESUMO

The present experiments were performed to investigate whether neurogenic inflammation in rat trachea (with edema formation and protein extravasation when the circulation is intact) induced by electrical field stimulation of neuropeptide-containing C fibers in the vagal nerve is accompanied by increased negativity of interstitial fluid pressure (P(if)). Increased negativity of P(if) in the trachea occurs in dextran anaphylaxis and mast cell degranulation and facilitates edema formation under these circumstances. Experiments were performed after circulatory arrest had been induced in pentobarbital anesthesia to prevent edema formation, which will raise P(if) and potentially cause underestimation of an increased negativity of P(if). After induction of circulatory arrest, the vagal nerve was isolated and placed in a stimulating electrode. The trachea was then exposed and covered with mineral oil, and measurement of P(if) was started as soon as possible thereafter. P(if) was measured with sharpened glass capillaries (tip diameter, 3 to 7 microns) connected to a servocontrolled counterpressure system. P(if) in the control group (n = 12) did not change throughout the observation period. Electrical stimulation of the left vagal nerve caused P(if) to fall in all experiments, from -1.1 +/- 1.1 mm Hg in the control condition to an average of -10.6 +/- 3.4 mm Hg (n = 9, P < .01). In some experiments, a continuous recording of P(if) was obtained, showing that the reduction of P(if) started within 30 seconds after onset of stimulation to reach and later remain at a stable level within a few minutes. The experimental protocol was repeated after the C fibers had been nearly depleted of neuropeptides with capsaicin.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Espaço Extracelular/fisiologia , Traqueia/inervação , Traqueíte/fisiopatologia , Animais , Peptídeo Relacionado com Gene de Calcitonina/análise , Estimulação Elétrica , Imuno-Histoquímica , Fibras Nervosas/fisiologia , Pressão , Ratos , Ratos Wistar , Substância P/análise
15.
Acta Anaesthesiol Scand ; 37(5): 465-8, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7741805

RESUMO

Endotracheal intubation conditions 60 s after intravenous administration of either high-dose vecuronium (0.3 mg kg -1; n = 25) or suxamethonium (1.0 mg kg -1; n = 25) were compared in a blind, randomised study. No significant differences were found between the two drugs. In 96% of the patients intubation conditions were characterized as excellent or good. In only one patient (4%) in each group were intubation conditions unsatisfactory. According to our findings, high-dose vecuronium provides satisfactory intubation conditions after 60 s and may be used instead of suxamethonium for rapid sequence intubation when a long duration of neuromuscular blockade is acceptable.


Assuntos
Intubação Intratraqueal/métodos , Succinilcolina , Brometo de Vecurônio/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
16.
J Appl Physiol (1985) ; 74(5): 2135-9, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8335540

RESUMO

The present study was performed to investigate whether the increased negativity of interstitial fluid pressure (Pif) observed after intravenous injection of dextran could be mediated via mast cell degranulation induced by C48/80 and polymyxin B sulfate. Increased negativity of Pif, concomitant with edema formation and increased albumin extravasation, was seen with both substances. However, the two substances differed in that polymyxin B sulfate induced less negativity in Pif and a larger but transient increase in capillary albumin extravasation and interstitial fluid volume. Total tissue water (TTW) increased from 2.11 to 2.71 ml/g dry wt 10 min after polymyxin B and returned to control level at 30 and 60 min. Injection of C48/80 increased TTW to 2.68 ml/g dry wt at 30 min, and TTW was still elevated at 60 min. Albumin extravasation followed a similar pattern; polymyxin B sulfate increased albumin extravasation from < 0.08 to 1.18 ml/g dry wt during the first 5 min after administration. C48/80 was less potent, and maximal albumin leakage was seen after 10-25 min (0.25 ml/g dry wt). The observations demonstrate the importance of the interstitium and the loose connective tissues as "active" participants in the edema-generating process and suggest an interaction with the structural components of the interstitium, as well as an important role for the mast cells in the chain of events creating increased negativity of Pif.


Assuntos
Degranulação Celular/fisiologia , Espaço Extracelular/fisiologia , Mastócitos/fisiologia , Traqueia/fisiologia , Albuminas/metabolismo , Animais , Água Corporal/metabolismo , Degranulação Celular/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Técnicas In Vitro , Mastócitos/efeitos dos fármacos , Polimixina B/farmacologia , Pressão , Ratos , Ratos Wistar , Decúbito Dorsal , Traqueia/citologia , Traqueia/efeitos dos fármacos , p-Metoxi-N-metilfenetilamina/farmacologia
17.
Acta Anaesthesiol Scand ; 36(3): 255-9, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1574974

RESUMO

Fluid transport between plasma and interstitium during extracorporeal circulation was studied in seven patients undergoing aortocoronary bypass grafting. The absolute shifts in plasma volume during hypothermia were determined as the difference between input and loss of fluid and the changes in blood volume. The change in haemoglobin concentration due to acute haemodilution when starting extracorporeal circulation was used to calculate the absolute blood and plasma volume. The Starling equation for exchange across the capillary wall was used to describe fluid shifts. The total fluid filtered during the 60- to 90-min period of extracorporeal circulation averaged 34.1 +/- 11.1 (s.d.) ml/min. The total body filtration coefficient from the Starling relationship averaged 0.046 +/- 0.012 ml/kg.mmHg.min (0.354 +/- 0.092 ml/kg.kPa.min). Haemodilution, reducing colloid osmotic pressure in plasma (COPP) by approximately 10 mmHg (1.3 kPa) will result in a loss of plasma fluid of around 2 1 per hour. When corrected for lower fluid viscosity due to hypothermia during extracorporeal circulation, CFC would be about 40% higher, and a filtered volume of nearly 3 1 in a normothermic 70-kg person would be expected. Crystalloid haemodilution for shorter periods of time does not produce excessive oedema and thus may be well tolerated.


Assuntos
Espaço Extracelular , Circulação Extracorpórea , Volume Plasmático , Idoso , Ponte de Artéria Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
J Appl Physiol (1985) ; 72(1): 53-7, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1371502

RESUMO

This study shows that, in rat trachea, dextran anaphylaxis is associated with increased negativity of interstitial fluid pressure (Pif) as measured with sharpened glass capillaries (tip diameter 3-7 microns) connected to a servo-controlled counterpressure system. Experiments were carried out in pentobarbital-anesthetized Wistar-Møller rats. Pif in the control situation was -2.5 +/- 0.38 (SD) mmHg. The mean pressure in animals killed 2 min after initiation of the anaphylactic reaction by injection of 1 ml of 10% Dextran 70 in 0.9% NaCl was -10.3 +/- 2.6 mmHg. In another experimental series, interstitial fluid volume was measured after dextran administration but without inducing circulatory arrest. Interstitial fluid volume increased from 0.94 +/- 0.16 to 1.56 +/- 0.42 ml/g dry wt after 10 min to 1.57 +/- 0.30 and 1.10 +/- 0.27 ml/g dry wt after 30 and 60 min, respectively. The increased negativity in Pif in tracheal mucosa in the early phase of dextran anaphylaxis will markedly increase the transcapillary net filtration pressure in the initial phase of edema development.


Assuntos
Anafilaxia/fisiopatologia , Traqueia/fisiopatologia , Anafilaxia/etiologia , Animais , Dextranos , Edema/fisiopatologia , Espaço Extracelular/fisiologia , Mucosa/fisiopatologia , Pressão , Ratos , Ratos Endogâmicos
19.
Acta Anaesthesiol Scand ; 35(1): 49-51, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2006598

RESUMO

The prospective registration of 200 percutaneous placements of permanent central venous catheters (Hickman catheters and subcutaneous infusion ports) was conducted in 172 patients aged 3 months-95 years. The insertions were reviewed to assess whether certain groups of patients or physicians were associated with more complications than others. Complications occurred in 16 patients (8.0%), of which 12 were arterial punctures. Two attempts (1%) at catheter placement failed. None of the complications required treatment. Of the catheter placements, 70% were performed by one of the three authors, and the rest by seven other experienced anesthesiologists. The complication rates were not different between the two groups. Nor was the complication rate significantly higher in small children. Percutaneous placement of permanent central venous catheters thus proved to be a safe and reliable technique, even in small children. The method is easily learnt by physicians experienced in central venous catheterization. Using this method, permanent venous access may be offered to a large number of patients.


Assuntos
Cateterismo Venoso Central/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cateterismo Venoso Central/efeitos adversos , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade
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