ABSTRACT
OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called ‘transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes. RESULTS: Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space. CONCLUSION: Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid. .
Subject(s)
Animals , Hemodynamics/physiology , Hyponatremia/physiopathology , Hypotension/physiopathology , Therapeutic Irrigation/adverse effects , Transurethral Resection of Prostate/adverse effects , Cardiac Output/drug effects , Diuretics, Osmotic/administration & dosage , Electrolytes , Glycine Agents/administration & dosage , Glycine/administration & dosage , Hyponatremia/etiology , Hypotension/etiology , Hypovolemia/etiology , Hypovolemia/physiopathology , Infusions, Intravenous , Kinetics , Mannitol/administration & dosage , Postoperative Complications/physiopathology , Swine , Syndrome , Time FactorsABSTRACT
PURPOSE: To evaluate hemodynamic effects of mannitol infusion in patients with acute intracerebral hemorrhage. METHODS: Thirty patients with acute intracerebral hemorrhage were enrolled. Transcranial doppler was used to detect variables of bilateral middle cerebral arteria (MCA) including mean velocity (Vm) and pulsitility index (PI) before and after125ml and 250ml mannitol infusion (0, 30, 60, 90, 120, 180, 240 min). RESULTS: When 125ml or 250ml mannitol was infused in patients with acute intracerebral hemorrhage, Vm of bilateral MCA elevated, and reached the top at 30min, and then decreased. PI decreased in the affected MCA (250ml) and in the unaffected MCA (125ml and 250ml). CONCLUSION: Mannitol infusion in patients with acute intracerebral hemorrhage can improve cerebral blood flow in bilateral hemispheres and decrease intracranial pressure in the hemorrhagic hemisphere (250ml) and in the nonhemorrhagic hemisphere (125ml and 250ml).
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cerebral Hemorrhage/therapy , Cerebrovascular Circulation/drug effects , Diuretics, Osmotic/administration & dosage , Hemodynamics/drug effects , Intracranial Pressure/drug effects , Mannitol/administration & dosage , Acute Disease , Diuretics, Osmotic/pharmacology , Echocardiography, Doppler, Pulsed , Infusions, Intravenous , Mannitol/pharmacology , Middle Cerebral Artery/drug effectsABSTRACT
Background: Continuous infusion of short life vasodilators are employed to test reversibility of pulmonary hypertension in cardiac transplant candidates. Sublingual isosorbide administration has not been described in the literature and it might be a simpler alternative. Aim: To evaluate sublingual isosorbide administration as a test of reversibility of pulmonary hypertension in heart failure. Patients and Methods: Prospective evaluation of patients referred for cardiac transplant evaluation. Patients underwent right catheterization for hemodynamic measurements at baseline and after repeated doses of 5 mg sublingual isosorbide every 5 minutes until observing a decrease in pulmonary vascular resistance decrease or symptomatic hypotension. Results: Twenty one patients, 18 men, age 49±15 years, were studied. Fourteen (66%) were transplanted. The mean sublingual isosorbide dose was 15±5 mg. After isosorbide administration, there was a significant decrease in mean arterial pressure (80±8.5 to 71±6.6 mmHg, p <0.0001), mean pulmonary artery pressure (38±11 to 26±7.8 mmHg, p <0.0001), systemic vascular resistance (1540±376 to 1277±332 dyn*s/cm5 p <0.001), pulmonary vascular resistance (3.5±2.2 to 2,5±1.6 Wood Units, p <0.05) and transpulmonary gradient (13±7 a 10±4 mmHg, p <0.004). The cardiac output increased from 3.96±0.7 to 4.38±0.9 L/min, p=0.05. The relation between pulmonary and systemic vascular resistance before and after isosorbide was 0.17 and 0.15, respectively (p=0.04). One transplanted patient with partial reversibility of pulmonary hypertension developed acute right heart failure. Conclusions: Sublingual isosorbide administration is useful and well tolerated to evaluate the reversibility of pulmonary hypertension prior cardiac transplant.
Subject(s)
Female , Humans , Male , Middle Aged , Cardiac Output, Low/surgery , Diuretics, Osmotic/administration & dosage , Heart Transplantation , Hypertension, Pulmonary/drug therapy , Isosorbide/administration & dosage , Vasodilator Agents/administration & dosage , Administration, Sublingual , Cardiac Output, Low/etiology , Cardiac Catheterization , Prospective StudiesSubject(s)
Administration, Oral , Adolescent , Cerebral Hemorrhage/diagnosis , Diuretics, Osmotic/administration & dosage , Female , Fluid Therapy , Follow-Up Studies , Hemiplegia/diagnosis , Humans , Injections, Intravenous , Mannitol/administration & dosage , Physical Therapy Modalities , Time Factors , Typhoid Fever/complicationsABSTRACT
En un estudio clínico aleatorizado se evaluaron 36 pacientes con preclampsia severa divididos en dos grupos de 18 pacientes c/u. Grupo A: Recibieron 1.25 mg de isosorbide en aerosol oral al ingreso, repitiéndose la dosis a los 10 minutos si la reducción en la presión arterial media fue < 15 por ciento, Grupo B: Recibieron sulfato de magnesio en infusión continua intravenosa, 4 g la primera hora y después un gramo por hora durante cinco horas. En ambos grupos se administró terapia con líquidos parenterales y se vigiló con monitor la presión arterial desde el ingreso, se determinó frecuencia cardiaca materna (FCM), fetal (FCF) y proteinuria antes y después del fármaco, así como el Apgar del producto al minuto y a los cinco minutos. El grupo A presentó disminución significativa de la presión arterial (p<0.0002), FCM (p<0.005), FCF (p<0.05), 13 pacientes con una aplicación y cinco con dos. En el grupo B tres pacientes no respondieron, y el resto tuvo un mal control de la presión arterial (p>0.05), sin cambios en FCM. FCM y proteinuria. En ningún caso hubo progresión a eclampsia. Al comparar ambos grupos entre sí, hubo una diferencia significativa para la presión arterial (<0.005), FCM (p<0.05), FCF (p<0.002) y Apgar al minuto (p<0.01) en el grupo con isosorbide. Los datos sugieren que el isosorbide es eficaz y seguro en el manejo de la preeclampsia severa
Subject(s)
Humans , Female , Pregnancy , Adult , Diuretics, Osmotic/administration & dosage , Hypertension/etiology , Hypertension/drug therapy , Isosorbide/administration & dosage , Pre-Eclampsia/complicationsABSTRACT
O diurético osmótico manitol é uma droga amplamente utilizada em neurociruriga e neurologia a fim de diminuir a pressäo intracraniana e melhorar a microcirculaçäo cerebral. As teorias sobre seu mecanismo de açäo säo revisadas: gradiente osmótico pela barreira hematoencefálica, auto-regulaçäo vascular e neutralizaçäo dos radicais livres do oxigênio. Sua posologia é empírica, segunda a experiência própria de cada autor. O conhecimento dos critérios básicos para o uso do manitol e de sua reposiçäo hidreletrolítica é fundamental para a manutençäo da osmolaridade sérica em valores terapêuticos