Uso combinado de alcalinização e tolazolina em recém-nascidos com hipertensão pulmonar persistente / Using alkalinization and tolazoline combination in pulmonary hypertension of the newborn

A hipertensão pulmonar (HP) do recém-nascido (RN) apresenta alta morbimortalidade. O objetivo deste estudo é relatar o uso de tolazolina combinada à alcalinização no tratamento da HP grave do RN. Este trabalho retrospectivo com RN com HP [pressão sistólica em artéria pulmonar (PAP) >=35 mmHg por ecocardiografia] abrangeu 4 anos. Os RN foram divididos em 2 grupos: GI - suporte ventilatório(O2 e/ou ventilação mecânica); GII - suporte ventilatório + drogas (tolazolina - ataque: 1/2 mg/kg, manutenção: 0,5 a 1 mg/kg/h e NaHCO3: 0,5-1 mEq/kg/h). A alcalinização e a tolazolina foram indicadas na ausência de resposta à hiperventilação (Pinsp >= 28 mmHg, FR >= 60/min), MAP (pressão média de vias aéreas) >= 14 mmHg e IO (índice de oxigenação) >= 20 por cento. A eficácia da terapêutica foi avaliada por diminuição dos parâmetros ventilatórios, MAP e IO (pré e pós o uso das drogas). Foram estudados 24 RN (GI:n=12, GII n=12). Os grupos não diferiram quanto à idade gestacional (médias: 354/7 e 36 3/7 sem) e peso de nascimento (médias: 2.560g e 2.799g). Em relação à citologia da HP obteve-se: asfixia - GI 3 (25 por cento), GII 2 (16,6 por cento); doença das membranas hialinas: GI 2 (16,6 por cento), GII (16,6 por cento); taquipnéia transitória: GI 1 (8,4 por cento); pneumotórax: GII 3 (25 por cento); síndrome de aspiração meconial: GII 2 (16,6 por cento); persistência de padrão fatal: GI 6 (50 por cento); hérnia diafragmática: GII 1 (8,4 por cento). A média das PAP foi de 52 mmHg (35-75) - GI e 66 mmHg (45-75) - GII.

Valor de la prueba de Tolazolina en el síndrome de la salida torácica con participación simpática

La agrupación de los distintos complejos sintomáticos bajo la denominación conjunto de síndrome de compresión del desfiladero torácico superior ha posibilitado el establecimiento de medidas diagnósticas y terapéuticas más precisas.Por lo que el servicio de Angiología y Cirugía Vascular del Hospital Provincial "Saturnino Lora" se ha propuesto lograr la validación y generalización de la PRUEBA DIAGNOSTICA DE LA TOLAZOLINA en el síndrome de la apertura superior del toráx con participación simpática, para determinar el dolor de origen simpático y diferenciarlo del dolor somático.De igual forma demostrar la necesidad de los estudios hemodinámicos,angioimagenológicos y neurofisiológicos para determinar los sitios exactos de comprensión y las estructuras vasculonerviosas afectadas y una vez logrado esto, encaminar un tratamiento combinado médico, fisioterapéutico y quirúrgico. La cirugia de la apertura superior del tórax cuando existe participación del simpatico, siempre ha de ser asociado a cirugía del simpático(simpatectomía dorsal o subestelectomía) por vía axilar

Isquemia intestinal por bajo flujo esplácnico / Low flow splachnic intestinal ischemia

El déficit circulatorio de este cuadro se ubica en la microcirculación intestinal por fallo de bomba, shock o uso de digital. Dolor abdominal repentino, distensión, enterorragia y los antecedentes llevan a la sospecha clínica y al diagnóstico. El tratamiento es en principio médico, con el esquema de Boley (Tolazolina y Papaverina), controlado por arteriografía; si no cede, el intestino necrótico debe ser removido quirúrgicamente. Material y Método: Se consideran 22 casos. Todos consultaron por dolor abdominal repentino, distensión y enterorragia. Sólo 3 carecían de antecedentes, los 19 restantes provenían de UTI, U.C., o tenían tratamiento con digital. Se utilizó el análisis univariable de variables cualitativas. Resultados: Se operaron 18 (81,8 por ciento), falleciendo sin operar 4 (18 por ciento). La mortalidad global fue de 15 (68,1 por ciento). Siete (31,8 por ciento) tuvieron buena evolución, ellos presentaron sólo lesiones de intestino delgado.

Nitroglycerin Treatment in Persistent Pulmonary Hypertension of the Newborn

PURPOSE: Persistent pulmonary hypertension (PPHN) of the newborn has been treated with some vasodilators including tolazoline. But these drugs have many side effects, especially systemic hypotension . To investigate the usefulness of the nitroglycerin as a specific vasodilator with few side effects, this study was done. METHODS: Nitroglycerin was administered within 1st one day after birth in 8 newborn infants who were diagnosed as PPHN by echocardiography. They were born at Il Sin hospital from March 1994 to March 1996. Nitroglycerin was started as 2microgram/kg/min and its maximum dose was 6microgram/kg/min. Muscle relaxants and inotropic drugs were used together in all cases. Arterial blood gas analysis, systemic blood pressure, heart rate, renal function and electrolyte were checked in all patients. Alveolar-arterial oxygen difference (AaDO2) and oxygenation index (OI) were measured. RESULTS: 6 cases (75%) survived but 2 cases expired due to air leak.1) Basal mean AaDO2 was 631.4+/-21.7mmHg. It decreased to 493.9+/-1453.1 mmHg at 10hr after loading infusion and to 373.6+/-217.7mmHg at 48hr (P<0.05). 2) Basal mean OI was 35.1+/-15.7 and it decreased significantly to 12.6+/-14.8 (P<0.05) at 10hr. 3) There was no significant hypotension in systolic, diastolic and mean blood pressure during treatment of nitroglycerin. 4) There was no significant change in renal function, serum electrolyte and heart rate during treatment of nitroglycerin. CONCLUSIONS: Nitroglycerin produced systemic venodilatation and pulmonary arterial dilatation at the dose that produce only minimal systemic arterial dilatation. Nitroglycerin is an effective and safe drug in the treatment of PPHN.

Isquemia intestinal no sectorial / Monocclusive mesenteric ischemia

El déficit circulatorio de este cuadro se ubica en la microcirculación intestinal por falla de bomba, shock o uso de digital. Dolor abdominal repentino, distensión, enterorragia y los antecedentes llevan a la sospecha clínica y al diagnóstico. El tratamiento es en principio médico, con el esquema de Boley (Tolazolina y papaverina), controlado por arteriografía; si no cede, el intestino necrótico debe ser removido quirúrgicamente. Se consideran 22 casos. Todos consultaron por dolor abdominal repentino, distensión y enterorragia. Sólo tres carecían de antecedentes, los 19 restantes provenían de terapia intensiva, unidad coronaria o tenían tratamiento con digital. Se utilizó el análisis univariable de variables cualitativas. Se operaron 18 (81,8 por ciento), falleciendo sin operar 4 (18 por ciento). La mortalidad global fue de 15 (68,1 por ciento). Siete (31,8 por ciento) tuvieron buena evolución, ellos presentaron sólo lesiones de intestino delgado

Antagonisation of xylazine using tolazoline in camels [camelus dromedarius]

Six clinically healthy camels were used to determine the effect of xylazine, followed by tolazoline as antagonist on respiratory rate, temperature, erythrocytic count, PCV%, Hb content and blood glucose level in camels. It was found that xylazine in a dose of 0.5 mg/kg B.W. resulted in certain changes as decreased respiratory rate, bradycardia, increase in blood glucose and changes in cell blood count. These changes can be reversed by tolazoline as antagonist in a dose of 1.5 mg/kg B.W

[Clinical evaluation on antagonistic effects of tolazoline on xylazine Hcl in calves]

To determine the antagonistic effects of tolazoline on xylazine Hcl sedation, 12 male Holstein calves of 8 to 12 months age with an average weight of 210 Kg were considered and arranged in 2 groups of 6 calves as the test and control groups. All calves were received an initial IM injection of xylazine Hcl [0.4 mg/Kg of 2% solution] followed in 15 minutes by IV injection of Tolazoline [2 mg/Kg of 10% solution] in test group and IV injection of the same volume of 0.9% normal saline in control calves. The significance reversal effects of tolazoline for xylazine Hcl on rectal temperature, heart and respiratory rates and recovery time [9.67 +/- 0.7 minutes] [P<0.05] indicated that, tolazoline is potentially enable to diminish the undesirable effects of xylazine Hcl such as prolonged sternal recumbancy with minimal complications

Urinary bladder serosal chemoreceptor induced cardio-respiratory responses: possible pathway.

There is limited experimental information about pain originating from the urinary bladder. In the present study application of 3-5 ml of 1% ammonium oxalate, 1% potassium chloride, 100m M citric acid, IM ammonium chloride, 1% oxalic acid, 0.5% sodium hydroxide, or 2 micrograms/ml bradykinin, to the serosal surface of the urinary bladder in anaesthetized dogs, resulted in an increase in heart rate, rise of both systolic and diastolic blood pressures and increase in respiratory rate and depth. These facilitatory cardio-respiratory responses were coupled with powerful contractions of the urinary bladder wall. By contrast, mucosal application of the chemicals did not bring about any significant change. The cardio-respiratory responses obtained were completely abolished on serosal application of procaine (1%), section of the hypogastric nerves or by spinalectomy at T8. Bilateral cervical vagotomy and pelvic nerve section did not modify the responses. However, the blood pressure responses were abolished by the administration of tolazoline hydrochloride, indicating a major role of sympathetics in this nociceptive reflex.

Effects of Central Dopaminergic Receptor-Activation on the Cardiovascular System

The central dopaminergic receptor is believed to suppress the cardiovascular system So it may be involved in the blood pressure regulation But, it's action is still controversial. Furthermore, the mechanisms involved in the central dopaminergic receptor-induced blood pressure regulation is unclear. So, present study was performed in order to clarify the effects of central dopaminergic receptor and to investigate the mechamisms involved in it. Lisuride a D2-receptor agonist, and clonidine, a alpha2-receptor agonist, were administered into lateral ventricle in rat and the changes of blood pressure were compared The results were as follows; 1. Intracerebroventricular administration of lisuride amd clonidine from 0.3 ug to 10 ug elicited dose related decrease of blood pressure and heart rate. The potencies were similar in both drugs. 2. Centrally administered sulpiride, a D2-antagonist, blocked only the lisuride-induced hypotension while the clonidine induced hypotension was blocked only by centrally adrninistered tolazoline, a alpha2-antagonist. Intravenous administration of both antagonists elicited no or minimal attenuabon of agonists effects. 3. After desipramine pretreatment, which increases the norepinephrine concentration lisuride elicited somewhat further decrease of blood pressure than normal, while clonidine administration caused rather increase in blood pressure. 4. After chemical sympathectomy by 6-hydroxydopamine, lisuride administration still elicited strong suppression of blood pressure. From thses above results, it is concluded that central dopaminergic receptor activation decrease the blood pressure. Suppression of the norepinephrine release at the sympathetic nerve terminal is not related with central dopaminergic receptor induced hypotension.

Effect of tolazoline on persistent hypoxemia in severe hyaline membrane disease

Ten critically-ill preterm infants with severe hyaline membrane disease received tolazoline because of persistent hypoxemia refractory to the administration of 100% oxygen and mechanical ventilation. Seven infants (70%) responded immediately with an increase in PaO2 greater than or equal to 20 mmHg in the umbilical arterial gas within 60 minutes after bolus infusion (1 to 2 mg/kg) of tolazoline. Twenty-four hours later after the tolazoline infusion, the FiO2 had been decreased from 1.0 to a mean of 0.82 +/- 0.16, and the MAP from 16.5 +/- 1.8 to 15.6 +/- 4.5 cm H2O. Four of 7 infants (57%) who had an immediate response survived, whereas none survived out of 3 infants who failed to respond initially. Three infants experienced relatively severe complications possibly related to tolazoline. There appears to be a place for the use of tolazoline in a severely hypoxemic infant with hyaline membrane disease who is being ventilated, and in whom arterial oxygenation cannot be improved by a further increase in the inspired oxygen concentration or by an alteration of ventilator settings.

Effect of adrenergic and cholinergic antagonists on post-hemorrhagic erythropoiesis in rats.

Experiments were carried out in albino rats to find out the effect of propranolol, priscol and atropine on post-hemorrhagic erythropoiesis. Administration of either propranolol or priscol decreased reticulocyte response following hemorrhage, whereas administration of atropine produced no change. The results indicate that alpha as well as beta adrenergic systems participate in the control of erythropoiesis following hemorrhage, whereas parasympathetic system does not take part.

Effect of tolazoline on xylazine induced hyperglycemia in rats

The present study was conducted on 40 albino rats to investigate the effect of the alpha adrenergic blocker "tolazoline" on the hyperglycemia and glucosurea experimentally induced by intramuscular injection of xylazine with a single dose of 16 mg/kg b. wt. in the tested rats. The estimated plasma glucose levels were 262.7 +/- 15.9 and 321.5 +/- 27.3 mg/dl at one and two hours following xylazine injection, respectively as compared with the levels [122.2 +/- 1.4 and 127.1 +/- 3.0] of non treated animals. Tolazoline [4 mg/kg b. wt. i. p.] completely antagonized the hyperglycemic effect induced by xylazine and the glucose level was significantly decreased to 114.3 +/- 9.9 and 107.1 +/- 4.8 mg/dl at one and two hours following xylazine injection, respectively as compared with xylazine treated group. Xylazine injection induced glucosurea and this effect can be antagonized by tolazoline injection. It is concluded that effect agent to counteract the tolazaective "an alpha [2] antagonist" is an hyperglycemic effect of xylazine. Moreover this study emphasis the role of alpha [2] receptors in regulation of blood glucose

Pathologic Changes of Peripheral Pulmonary Arteries in Ventricular Septal Defect with Pulmonary Hypertension

Twelve patients with ventricular septal defect with pulmonary hypertension underwent lung biopsy to assess pulmonary obstructive vascular disease at the time of open heart surgery. According to the Heath and Edwards classification in grading of Pulmonary obstructive vasculr disease, there are eleven cases in grade 1 and one case in grade 3. Thickness of media was measured. It was expressed as percentage of medial thickness to outer diameter of artery. The medial thickness was correlated proportionally with elevation of pulmonary arterial pressure and pulmonary vascular resistance to systemic resistance ratio. In tolazoline test performed in 4 cases, one patients who had pulmonary obstructive vascular disease, had no change of pulmonary vascular resistance to systemic vascular resistance after intravenous injection of tolazoline during cardiac catheterization, but Rp/Rs of three cases was decreased significantly.