Catecholamine-induced vasoconstriction is sensitive to carbonic anhydrase I activation

We studied the relationship between alpha- and beta-adrenergic agonists and the activity of carbonic anhydrase I and II in erythrocyte, clinical and vessel studies. Kinetic studies were performed. Adrenergic agonists increased erythrocyte carbonic anhydrase as follows: adrenaline by 75 percent, noradrenaline by 68 percent, isoprenaline by 55 percent, and orciprenaline by 62 percent. The kinetic data indicated a non-competitive mechanism of action. In clinical studies carbonic anhydrase I from erythrocytes increased by 87 percent after noradrenaline administration, by 71 percent after orciprenaline and by 82 percent after isoprenaline. The increase in carbonic anhydrase I paralleled the increase in blood pressure. Similar results were obtained in vessel studies on piglet vascular smooth muscle. We believe that adrenergic agonists may have a dual mechanism of action: the first one consists of a catecholamine action on its receptor with the formation of a stimulus-receptor complex. The second mechanism proposed completes the first one. By this second component of the mechanism, the same stimulus directly acts on the carbonic anhydrase I isozyme (that might be functionally coupled with adrenergic receptors), so that its activation ensures an adequate pH for stimulus-receptor coupling for signal transduction into the cell, resulting in vasoconstriction

Severe Hypercapnia Occurred by Anesthetized Child with Treated Bronchitis during an Operation for Bilateral Hutch's Diverticulum of Bladder: A case report / 대한마취과학회지

A 23-month-old male patient with treated bronchitis underwent a surgery for the repair of bilateral Hutch's diverticulum of bladder under general anesthesia. He treated bronchitis during 2 weeks since 3 weeks before operation. Arriving operating room, he had mild coughing with sputum. During anesthesia, he was well ventilated but endotracheal secretion was profuse. At ABGA of 2 hours after starting anesthesia, severe hypercapnea(PaCO2: 190.2 mmHg) and severe acidosis(PH: 6.746) were checked. Active treatment was done by suction of endotracheal secretion, hyperventilation, PEEP(5~10 cmH2O), increasing fresh gas flow rate(3.6 L/min --> 7 L/min), and administration of sodium bicarbonate, orciprenaline sulfate and methyl- prednisolone. After 3 hours of treatment, ABGA was normalized and symptoms including wheezing were relieved.

Effects of nebulized beta 2-adrenergic agonists on pulmonary mechanics in anesthetized patients with chronic obstructive pulmonary disease.

We evaluated the effects of nebulized beta 2-adrenergic agonists on pulmonary mechanics in patients with COPD undergoing peripheral surgery with a standardized general anesthetic technique. Thirty males with COPD were randomized into one of three groups. Group I (control group; n = 10) received nebulized saline 3 ml, Group II (n = 10) received nebulized albuterol (2.5 mg in 3 ml), and Group III (n = 10) received nebulized metaproterenol (15 mg in 3 ml). At 20 min after tracheal intubation, the study drugs were nebulized over 20 min. Datex Capnomac Ultima monitor was used to measure pulmonary mechanics on a breath-by-breath basis. There was no difference between the three groups with respect to demographic data and preoperative respiratory parameters. A similar degree of DPH occurred with the initiation of mechanical ventilation in all three groups. Patients receiving nebulized bronchodilators (Groups II and III) displayed a significant decrease in DPH and an increase in total dynamic compliance. However, there were no differences in DPH and total dynamic compliance between Groups II and III. We conclude that nebulization of either albuterol or metaproterenol can alleviate DPH resulting from mechanical ventilation in anesthetized patients with COPD.

Carotid sinus syndrome associated with carcinoma of the pyriform fossa.

A patient who developed syncope due to carotid sinus syndrome is described. The patient was suffering from carcinoma of the pyriform fossa for the past one year and received radiotherapy in the region of the neck for the same. Demand pacing was ineffective in alleviating syncopal episodes. The patient responded to oral administration of an anticholinergic (belladonna) and a sympathomimectic agent (orciprenaline).

Bloqueo aurículo ventricular completo en el hipertiroidismo / Complete heart block and hyperthyroidism

Se presenta el caso de una paciente portadora de una Enfermedad de Basedow que desarrolló bloqueo aurículo ventricular (AV) completo sintomático, requiriendo de la instalación de sonda marcapaso transitoria. En ella existía sólo el antecedente de infección de faringe previo. La conducción AV fue normal una vez eutiroídea. Se señala lo comunicado en la literatura en relación a la génesis del trastorno. Se destaca la importancia de evitar fármacos que puedieran aumentar el deterioro de conducción en aquellos pacientes hipertiroídeos con PR largo y prescindir de terapia definitiva ya que invariablemente se normaliza la conducción AV al lograr eutiroidismo

Ensayo clinico con broncodilatadores en bronquitis obstructiva del lactante y preescolar menor. / Clinical trial with bronchodilator agents in obstructive bronchitis of infants and preschool children

Con el objeto de evaluar la respuesta con broncodilatores en ninos menores con bronquitis obstructiva, se realizo un estudio clinico con fenoterol y metaproterenol, comparandolo con un grupo control. El analisis estadistico de cada parametro clinico demostro diferencia significativa solamente en relacion al descenso de la frecuencia respiratoria con el uso de estimulantes beta-adrenergicos con respecto a los controles. En los demas parametros no se demostro diferencia estadisticamente significativa entre el grupo con broncodilatores y el grupo control. Por lo tanto, este estudio corrobora la utilidad limitada del uso de broncodilatores en bronquitis obstructiva, traducida un una disminucion de la frecuencia respiratoria, que indirectamente demuestra una disminucion de la resistencia al flujo aereo, hecho que deberia ser confirmado con pletismografo

Prevencion del parto prematuro con drogas uteroinhibidoras. / Prevention of premature labor with utero-inhibitor drugs

Se estudiaron 131 pacientes con diagnostico de ingreso de amenaza de parto prematuro, en los cuales se utilizaron las drogas beta mimeticas etil adrianol, orciprenalina y terbutalina. Se compararon con un grupo control de 296 pacientes en las cuales no se utilizaron drogas. Se observo una prolongacion de la gestacion en promedio de 5.1 semanas en el grupo tratado. Aunque la letalidad general es alta, la letalidad corregida es satisfactoria en el grupo tratado. Los efectos colaterales de las drogas son mayores durante su uso por via endovenosa y disminuye considerablemente con la administracion oral de los medicamentos. Dado que el uso de estos farmacos esta aun en la fase de evaluacion debe procederse con cautela en la indicacion, e individualizar los casos. El auxilio de metodos de laboratorio y gabinete es indispensable para valorar adecuadamente la funcion placentaria y el grado de madurez fetal para decidir en que pacientes deben utilizarse uteroinhibidores