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At least 361 records · Page 20Linked to original sources
PubMed1989

Preliminary hemodynamic report of the efficacy and safety of quinapril in acute and chronic treatment of patients with congestive heart failure.

A two-part hemodynamic trial of the efficacy and safety of quinapril hydrochloride was conducted in 26 patients with congestive heart failure (NYHA Class III or IV) who had not optimally responded to treatment with diuretics and digitalis. A total of 25 patients had evaluable data after receiving single doses (2.5, 5, or 10 mg) of quinapril. Following acute dosing, favorable hemodynamic changes began within thirty minutes to one hour and usually reached a maximum within four hours post-dose. Nineteen evaluable patients who had responded to acute therapy received an additional sixteen weeks of chronic treatment with quinapril in individualized dosage regimens. Hemodynamic responses did not differ markedly between acute and chronic therapy. Favorable hemodynamic responses were maintained or enhanced following chronic doses of 5 to 30 mg/day (given either once daily or in divided doses). The most frequent doses were 10-15 mg/day in divided doses. The mean maximum percent changes in four primary hemodynamic parameters after chronic dosing (compared with baseline) were: mean arterial blood pressure, -3.9%; pulmonary capillary wedge pressure, -39.7%; cardiac output, +31.7%; and systemic vascular resistance, -25.2%. Changes in heart rate and mean arterial blood pressure did not result in clinically significant bradycardia or hypotention. Overall, quinapril produced both acute and sustained beneficial hemodynamic effects in patients whose congestive heart failure was not clinically controlled with diuretics and digitalis.

Adult↗
PubMedDate not supplied

Lens model analysis of hemodynamic status in the critically ill.

The lens model recently has been extended to consider multiple outcomes and sequential use of clinical information. The authors have used this extended model 1) to describe the relationship between clinical information and physicians' assessments of hemodynamic status, 2) to describe the empirical relationship between clinical information and physiologic measures of hemodynamic status, and 3) to compare physicians' use of information with its empirical utility. Physicians prospectively provided estimates of cardiac index and pulmonary capillary wedge pressure for 440 intensive care unit patients prior to right heart catheterization. The correlation between physicians' estimates and measured hemodynamic status was lower than that between clinical information and hemodynamic status (0.42 versus 0.67). Only 7% of physicians' judgement was related to subsequent ancillary testing. Empirically, subsequent ancillary testing contributed 30% to the explanation of hemodynamic status. The lens model describes limitations of physician judgement in estimating left ventricular function and helps explain how patient features relate to measured hemodynamic status.

Cardiac Catheterization↗
PubMed2003

Omapatrilat induces profound renal vasodilation but does not affect coronary hemodynamics.

BACKGROUND: Omapatrilat has potent enzymatic inhibitory effects on the angiotensin-converting enzyme and neutral endopeptidase. The prolonged effects of this inhibition on systemic and regional hemodynamics, cardiovascular mass, and hydroxyproline concentration in spontaneously hypertensive rats were studied. The contribution of endogenous bradykinin on the cardiovascular actions of omapatrilat in this genetic model of hypertension was also investigated. METHODS AND RESULTS: Systemic and regional hemodynamics (radionuclide-labeled microspheres), left and right ventricular and aortic masses, and hydroxyproline concentration were determined in 35-week-old spontaneously hypertensive rats after 12 weeks of treatment with omapatrilat (40 mg/kg/day), with and without the bradykinin receptor antagonist icatibant (500 microg/kg/day). Omapatrilat decreased mean arterial pressure, reducing total peripheral resistance as well as decreased left ventricular and aortic mass indices. It also induced a profound renovasodilation associated with a decrease renal vascular resistance that markedly increased renal blood flow. Coronary hemodynamics and left ventricular hydroxyproline concentration remained unaltered. Concomitant blockade of bradykinin receptors partially attenuated the hypotensive effect of omapatrilat and its effect on aortic mass; and icatibant did not influence the renovasodilation. CONCLUSION: Omapatrilat produced profoundly beneficial effects on systemic and renal hemodynamics, as well as on left ventricular and aortic masses, without any effect on coronary hemodynamics. These effects of omapatrilat on arterial pressure and aortic mass, but not on renal hemodynamics and left ventricular mass, may have been at least partially mediated through the action of bradykinin.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

A comparison of hemodynamic changes during the transition from mechanical ventilation to T-piece, pressure support, and continuous positive airway pressure in canines.

The immediate transition from positive pressure mechanical ventilation to spontaneous ventilation may generate significant cardiopulmonary hemodynamic alterations based on the mode of weaning selected, particularly in individuals with preexisting cardiac dysfunction. The purpose of this study was to compare hemodynamic responses associated with the initial transition to 3 modes of ventilator weaning (spontaneous ventilation/T-piece, pressure support [PS], and continuous positive airway pressure [CPAP]). Right ventricular hemodynamic responses were evaluated with a thermodilution pulmonary artery catheter; while left ventricular hemodynamic responses were measured by a transducer-tipped Millar catheter and conductance catheter. Two groups of canines were studied. Group 1: normal biventricular function (n = 10) and group 2: propranolol-induced biventricular failure (n = 10). Dependent variables were measured at baseline on controlled mechanical ventilation (MV) and following the initial transition to each of 3 randomized spontaneous ventilatory conditions: T-piece, PS 5 cmH2O, and CPAP 5 cmH2O. Both groups significantly increased cardiac output in response to T-piece. Right ventricular stroke work was also significantly increased with T-piece and CPAP in both groups of subjects. Left ventricular response depended on baseline ventricular function. Baseline ventricular function influenced hemodynamic response to the immediate transition from mechanical to spontaneous ventilation. There were also differential hemodynamic responses based on the ventilatory mode. Consideration of baseline cardiac function may be an important factor in the selection of an appropriate mode of spontaneous ventilation following controlled MV.

Animals↗
PubMed2003

Resolution and outcome of acute circulatory failure does not correlate with hemodynamics.

INTRODUCTION: Hemodynamic goals in the treatment of acute circulatory failure (ACF) are controversial. In critical care, organ failures can be assessed using Sequential Organ Failure Assessment and its refinement, total maximal Sequential Organ Failure Assessment (TMS). We studied the associations between resolution of ACF and hemodynamics in the early (< 24 hours) phase of intensive care unit care and their relation to TMS and mortality. PATIENTS AND METHODS: Eighty-three patients with ACF (defined as arterial lactate > 2 mmol/l and/or base deficit > 4) who had pulmonary artery catheters and stayed for longer than 24 hours in the intensive care unit were included. Hemodynamics, oxygen transport, vasoactive drugs and TMS scores were recorded. Normalisation of hyperlactatemia and metabolic acidosis in less than 24 hours after admission was defined as a positive response to hemodynamic resuscitation. RESULTS: Fifty-two patients responded to resuscitation. Nonresponders had higher mortality than responders (52% versus 33%, P = 0.044). Hospital mortality was highest (63%) among nonresponders who received vasoactive drugs. The TMS scores of nonresponders (median [interquartile range], 12 9-16) were higher than the scores of responders (10 7-12, P = 0.019). Late accumulation of TMS scores was associated with increasing mortality, and if the TMS score increase occurred > 5 days after admission then the mortality was 77%. Responders had higher mean arterial pressure at 24 hours, but it was no different between survivors and nonsurvivors. No other hemodynamic and oxygen transport variables were associated with the success of resuscitation or with mortality. CONCLUSIONS: Except for the mean arterial pressure at 24 hours, invasively derived hemodynamic and oxygen transport variables are not associated with the response to resuscitation or with mortality. Positive response to resuscitation in ACF is associated with less severe organ failures as judged by TMS scores. Late accumulation of the TMS score predicts poor outcome.

Acidosis, Lactic↗
PubMed2005

Functional hemodynamic monitoring.

Hemodynamic monitoring is a central component of intensive care. Patterns of hemodynamic variables often suggest cardiogenic, hypovolemic, obstructive, or distributive (septic) etiologies to cardiovascular insufficiency, thus defining the specific treatments required. Monitoring increases in invasiveness, as required, as the risk for cardiovascular instability-induced morbidity increases because of the need to define more accurately the diagnosis and monitor the response to therapy. Monitoring is also context specific: requirements during cardiac surgery will be different from those in the intensive care unit or emergency department. Solitary hemodynamic values are useful as threshold monitors (e.g. hypotension is always pathological, central venous pressure is only elevated in disease). Some hemodynamic values can only be interpreted relative to metabolic demand, whereas others have multiple meanings. Functional hemodynamic monitoring implies a therapeutic application, independent of diagnosis such as a therapeutic trial of fluid challenge to assess preload responsiveness. Newer methods for assessing preload responsiveness include monitoring changes in central venous pressure during spontaneous inspiration, and variations in arterial pulse pressure, systolic pressure, and aortic flow variation in response to vena caval collapse during positive pressure ventilation or passive leg raising. Defining preload responsiveness using these functional measures, coupled to treatment protocols, can improve outcome from critical illness. Potentially, as these and newer, less invasive hemodynamic measures are validated, they could be incorporated into such protocolized care in a cost-effective manner.

Blood Pressure Determination↗
PubMed1991

Hemodynamic responses to endotracheal extubation after coronary artery bypass grafting.

After coronary artery bypass grafting (CABG) surgery, patients may remain at risk for myocardial ischemia and infarction and ventricular dysrhythmias. The hemodynamic responses to endotracheal extubation and the efficacy of intravenous lidocaine pretreatment were studied after CABG surgery and overnight mechanical ventilation. Twenty-five patients were divided into two groups: group 1 (n = 13) patients who had tracheal extubation after pretreatment with a placebo; group 2 patients who received lidocaine (1 mg/kg IV) before tracheal extubation. Hemodynamic data, electrocardiographic tracings, and arterial blood gases were obtained before tracheal extubation, during suctioning, and 1, 5, and 20 min after tracheal extubation. Group 1 patients displayed significant increases in heart rate, arterial blood pressure, rate-pressure product, right atrial pressure, and cardiac index during suctioning and within 1 min of tracheal extubation, returning to preextubation level by 5 min. There were no significant changes in pulmonary and systemic resistance indices. Hemodynamic changes in group 2 patients were similar to those in group 1. Both in the absence and presence of lidocaine, tracheal extubation caused hemodynamic responses that were small in magnitude and brief in duration. These responses were not associated with electrocardiographic or enzymatic evidence of myocardial ischemia or infarction, or with ventricular dysrhythmias. Compared with the well-documented hemodynamic responses to tracheal intubation, we found that extubation of the trachea after CABG surgery was associated with less pronounced responses. This may be related to avoidance of laryngoscopy and possibly accommodation to the endo-tracheal tube. These modest hemodynamic responses of extubation of the trachea after CABG surgery were not modified by intravenous lidocaine.

Coronary Artery Bypass↗
PubMed2000

[New method for evaluating the effects of neuroprotective therapy in the hemodynamic penumbra].

Recently, we established a novel temporal correlation mapping (TCM) technique in combination with high-resolution functional computed tomography (CT) scanning to analyze the temporal changes in bolus transit dynamics of iodinated contrast agents in focal cerebral ischemia. Based on changes in the temporal dynamics of blood flow, we defined a new kind of penumbra and core in focal ischemia: the hemodynamic penumbra and hemodynamic core. We visualized for the first time a larger hemodynamic core and smaller hemodynamic penumbra in endothelial NOS knockout mice than in wild type mice early after focal ischemia by using the TCM analysis technique. In addition, neuroprotective effects of the water-soluble AMPA receptor antagonist YM872 were for the first time observed in the hemodynamic penumbra after focal ischemia. In conclusion, early TCM analysis could be used to directly and quantitatively evaluate the effects of neuroprotective therapy and the evolution of neuronal damage in the hemodynamic penumbra.

Animals↗
PubMed1999

Dobutamine in severe scorpion envenomation: effects on standard hemodynamics, right ventricular performance, and tissue oxygenation.

OBJECTIVES: To document the effects of dobutamine on standard hemodynamics and right ventricular (RV) performance in patients exhibiting pulmonary edema following severe scorpion envenomation, and to characterize the tissue oxygenation profile in patients sustaining scorpion envenomation-related shock. DESIGN: Prospective cohort study. SETTING: An ICU in a university hospital. PATIENTS: Nineteen consecutive patients were admitted to the ICU for severe scorpion envenomation; all 19 patients exhibited hemodynamic pulmonary edema, and 10 patients had peripheral shock. INTERVENTIONS: All patients underwent a hemodynamic study with a Swan-Ganz catheter. In 8 of 19 patients, the thermodilution catheter was equipped with a fast-response thermistor. MEASUREMENTS AND RESULTS: Standard hemodynamic parameters were recorded on admission and following the infusion of dobutamine in all patients at a dosage, from 7 to 20 microg/kg/min, intended to achieve the best hemodynamic and tissue oxygenation compromise. RV ejection fraction (RVEF) and RV volumes were simultaneously recorded in 8 patients, and tissue oxygenation parameters were assessed in the 10 patients with peripheral shock. The clinical signs of tissue hypoperfusion improved, and optimal hemodynamic parameters were achieved at a mean +/- SD dobutamine dosage of 17 +/- 7 microg/kg/min. Dobutamine infusion evoked statistically significant increases in cardiac index, from 2.3 +/- 0.6 to 3.6 +/- 0.7 L/min/m2; stroke volume index, from 18 +/- 5 to 31 +/- 10 mL/m2; and systemic arterial pressure, from 64 +/- 12 to 78 +/- 14 mm Hg. Pulmonary artery occlusion pressure (PAOP) and venous admixture decreased significantly: from 23 +/- 4 to 15 +/- 6 mm Hg and from 29 +/- 7% to 20 +/- 5%, respectively. With respect to RV function, dobutamine infusion significantly increased the RVEF, from 24 +/- 7% to 42 +/- 9%, without significantly changing the RV end-diastolic volume index, reflecting an enhanced RV contractility. In patients with peripheral circulatory failure, the baseline tissue oxygenation profile was consistent with cardiogenic shock, showing increased oxygen extraction as a consequence of a striking depression in oxygen delivery (DO2). After dobutamine infusion, DO2 improved significantly, from 386 +/- 104 to 676 +/- 156 mL/min/m2, with a significant decrease in oxygen extraction, from 34 +/- 8% to 24 +/- 6%. CONCLUSIONS: In severe scorpion envenomation, dobutamine infusion improves impaired heart function. The effects involve both left ventricular and RV dysfunction. Impaired tissue oxygenation is also improved.

Acute Disease↗
PubMed2002

Implications of the hemodynamic optimization approach guided by right heart catheterization in patients with severe heart failure.

OBJECTIVE: To report the hemodynamic and functional responses obtained with clinical optimization guided by hemodynamic parameters in patients with severe and refractory heart failure. METHODS: Invasive hemodynamic monitoring using right heart catheterization aimed to reach low filling pressures and peripheral resistance. Frequent adjustments of intravenous diuretics and vasodilators were performed according to the hemodynamic measurements. RESULTS: We assessed 19 patients (age = 48+/-12 years and ejection fraction = 21+/-5%) with severe heart failure. The intravenous use of diuretics and vasodilators reduced by 12 mm Hg (relative reduction of 43%) pulmonary artery occlusion pressure (P<0.001), with a concomitant increment of 6 mL per beat in stroke volume (relative increment of 24%, P<0.001). We observed significant associations between pulmonary artery occlusion pressure and mean pulmonary artery pressure (r=0.76; P<0.001) and central venous pressure (r=0.63; P<0.001). After clinical optimization, improvement in functional class occurred (P< 0.001), with a tendency towards improvement in ejection fraction and no impairment to renal function. CONCLUSION: Optimization guided by hemodynamic parameters in patients with refractory heart failure provides a significant improvement in the hemodynamic profile with concomitant improvement in functional class. This study emphasizes that adjustments in blood volume result in immediate benefits for patients with severe heart failure.

Adult↗
PubMedDate not supplied

Hemodynamic monitoring in the care of the critically ill neuroscience patient.

Hemodynamic monitoring in the care of the critically ill neuroscience patient provides information that assists the clinician in minimizing secondary neuronal injury. Whereas no technology replaces the critical care nurse's physical assessment, hemodynamic and neurological monitoring provides additional data beyond what is possible with the clinical examination alone. If neurological technology, such as intracranial pressure monitoring, is not available, hemodynamic monitoring along with the neurological examination provides limited but useful information essential to minimizing secondary neuronal injury. The use of hemodynamic monitoring in critically ill neuroscience patients is best exemplified in the management of cerebral vasospasm after aneurysmal subarachnoid hemorrhage. Although improved outcomes have not been scientifically substantiated, multimodality monitoring of intracranial dynamics and systemic hemodynamics and manipulation of these parameters during hypertensive hypervolemic hemodilution therapy may lessen the incidence of cerebral infarction secondary to vasospasm. Monitoring systemic hemodynamics and intracranial dynamics simultaneously assists in prevention, prompt recognition, and effective treatment of neurological deterioration.

Brain Ischemia↗
PubMed1999

[Effects of melatonin alone and in combination with aceten on chronostructure of diurnal hemodynamic rhythms in patients with hypertension stage II].

AIM: To study effects of monotherapy with melatonin and combination melatonin + aceten on circadian pattern of hemodynamics in patients with essential hypertension stage II. MATERIALS AND METHODS: 20 EH patients were randomized into 2 groups, 10 patients each. Group 1 patients were given melatonin alone (6 mg at 22.00). Group 2 received aceten (25 mg at 18.00) and melatonin (6 mg at 22.00). Before treatment and after 10 days of it, hemodynamic parameters were measured each 3 hours for 24 hours. Arterial pressure was measured by Korotkov method, heart rate--by ECG R-R interval, stroke volume--by tetrapolar chest rheography according to Kubichek. Cardiac index, total and specific peripheral resistance, double product were estimated routinely. RESULTS: Internal and external dyssynchronism was registered in hemodynamic parameters of EH patients. Melatonin normalized circadian hemodynamic rhythms. It produced a hypotensive effect, reduced energy requirements of the myocardium. Combination of melatonin with aceten had a hypotensive and vasodilating effects but failed to restore circadian hemodynamic rhythms. CONCLUSION: Melatonin, epiphysial neurohormone, and its combination with aceten have hypotensive and vasodilating effects but melatonin monotherapy normalizes circadian hemodynamic rhythms while the combination was uneffective in this respect. This may be explained by interaction of melatonin and aceten actions.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

[Effectiveness of hemodynamic treatment guided by gastric intramucosal pH monitoring].

OBJECTIVE: To determine whether gastric intramucosal pH can be used as an indicator for the treatment of critically ill children. METHODS: A protocol for hemodynamic treatment was tested in 34 critically ill children (medical and surgical patients). Endpoint was considered as normalization of gastric intramucosal pH. Hemodynamic complications were compared with another group of critically ill patients who received conventional treatment. RESULTS: Treatment designed to improve tissue oxygenation (hemodynamic stabilization, volume expansion, and dobutamine perfusion) raised pHi values from 7.25 +/- 0.04 to 7.32 +/- 0.13 (p = 0.014). Seventy-three percent of the children with pHi < 7.30 presented hemodynamic complications. These findings were compared with the results obtained in a control group of 30 critically-ill children given conventional treatment in the pediatric intensive care unit. In this group, 93.8% of the children with a pHi < 7.30 developed hemodynamic complications. CONCLUSIONS: We conclude that gastric intramucosal pHi can be useful as an indicator for the hemodynamic treatment of critically ill children.

Adolescent↗
PubMedDate not supplied

The hemodynamics of dysplastic nodules in the liver evaluated by CT angiography and immunohistochemistry.

BACKGROUND/AIMS: Dysplastic nodules diagnosed pathologically exhibit various hemodynamic patterns. To evaluate these differences in their hemodynamics, we observed basement membrane formation of sinusoids. METHODOLOGY: For 12 low-grade dysplastic nodules, 24 high-grade dysplastic nodules and 16 hepatocellular carcinomas, both computed tomography during arterial portography and CT arteriography were performed preoperatively. Resected specimens were examined immunohistochemically for COL IV (type IV collagen) and laminin to observe basement membrane formation. We compared their hemodynamics on computed tomography during arterial portography and CT arteriography with the expressions of COL IV and laminin. RESULTS: All of the low-grade dysplastic nodules were not hypervascular on CT arteriography, and negative for COL IV and laminin. All of the hepatocellular carcinomas were hypervascular on CT arteriography, and positive for COL IV and laminin. High-grade dysplastic nodules exhibit four hemodynamic patterns on CT during Arterial Portography/CT arteriography. All of 7 iso/iso and 5 iso/hypo nodules were negative for COL IV and laminin. Of the 9 hypo/hyper nodules, which exhibited hemodynamics similar to hepatocellular carcinoma, COL IV was identified in 7 and laminin identified in 8 nodules. Of the 3 hypo/hypo nodules, COL IV and laminin were identified in one. CONCLUSIONS: In high-grade dysplastic nodules, most cases exhibited a correlation between the hemodynamic patterns and the degree of the sinusoidal basement formation.

Aged↗
PubMed2000

[Is a totally non-invasive assessment of the hemodynamic profile possible in patients with chronic heart failure?].

Relevant hemodynamic information can be obtained by a comprehensive Doppler echocardiographic examination in patients with various cardiac diseases. The assessment of left heart hemodynamics by Doppler echocardiography has been addressed by several investigators. The feasibility and the accuracy of methods for the estimation of left ventricular filling pressure and cardiac output have been validated by comparative right heart catheterization. Studies have shown that Doppler echocardiography can allow the measurement of pulmonary artery pressures from the pressure gradients across the tricuspid and pulmonary valves. The possibility of completely characterizing cardiac hemodynamics noninvasively has recently been documented: in patients with acute myocardial infarction, automated cardiac output measurement along with the assessment of left ventricular filling by Doppler echocardiography may be used for the identification of hemodynamic subsets. Although Doppler echocardiography can provide noninvasive measures of hemodynamic indices, its value has been disputed since the technique is patient-dependent, time-consuming and requires meticulous acquisition and interpretation by skilled operators. The use of contrast agents may improve the accessibility of both right-sided and left-sided Doppler signals, potentially increasing the number of patients to whom the noninvasive hemodynamic assessment could be applied.

Chronic Disease↗
PubMedDate not supplied

Cerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study.

BACKGROUND AND PURPOSE: Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI). METHODS: Nine patients with asymptomatic unilateral ICA occlusion underwent DSC-MRI and TCD examination. One patient was excluded from final analysis because of severe movement artifacts. On a separate workstation, regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean time to peak (rMTT) were calculated on the basis of signal decay rate during the passage of gadolinium bolus through the sampled volume in the territory of the middle cerebral artery. TCD-BHI was calculated in all patients. Six healthy subjects underwent the same MR protocol as the patients. RESULTS: Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: rCBF was significantly lower than in controls (P <.01), and r MTT was significantly increased in both white (WM) and gray matter (GM) in the affected side (WM: P <.01; GM: P <.05). No statistically significant difference in rCBV was found in the group of patients (occluded versus contralateral, P <.1) or between the patient and control groups (occluded side versus controls, P <.1). The correlation of rCBV and BHI showed a strong relation of the two variables, showing a decrease of the latter when the former increased. CONCLUSION: DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.

Angiography, Digital Subtraction↗
PubMed1992

Intrarenal hemodynamic abnormality in severe form of glomerulonephritis: therapeutic benefit with vasodilators.

Intrarenal hemodynamic and tubular function has been assessed in 16 patients who presented clinically with hypertension, hematuria and severe renal functional impairment. Twelve of these 16 patients had histopathologic classification as DPGN (3 cases), MPGN (3 cases) and FSGS (6 cases). The initial assessment of intrarenal hemodynamics in 11 patients revealed strikingly increased afferent (RA) and efferent arterioles (RE), filtration fraction (FF), intraglomerular capillary hydrostatic pressure (PG), whereas, there was marked reduction in renal plasma flow (RPF), in ultrafiltration coefficient (KFG) and in glomerular filtration rate (GFR). Tubular transporting defect as being reflected by enhanced fractional excretions of solutes was also observed. Both enhanced TXB2 production and diminished PGI2 may be in part responsible for the marked reduction of RPF and elevated intrarenal resistance. In light of the preceding intrarenal hemodynamics alteration, therapeutic intervention with vasodilators consisting of dipyridamole, calcium channel blocker and angiotensin convertase inhibitor has been accomplished with clinical improvement in glomerular and tubular functions following the improvement in intrarenal hemodynamics. Thus, this abnormal intrarenal hemodynamics renders a supportive view of the hemodynamically mediated glomerulo-tubulo-interstitial injury to be central to the pathogenetic mechanism.

Adolescent↗
PubMed1992

Hemodynamic effects of GI 87084B, an ultra-short acting mu-opioid analgesic, in anesthetized dogs.

Hemodynamic effects of GI 87084B, a novel ultra-short acting mu-opioid agonist, were studied in anesthetized dogs. In these studies, GI 87084B (0.3-20 nmol/kg/min i.v.) produced dose-dependent decreases in heart rate, arterial blood pressure, +dP/dt and cardiac output. Alfentanil produced similar effects but was less potent. After termination of the infusions (397 nmol/kg cumulative dose), the hemodynamic effects of GI 87084B dissipated over 30 to 40 min. The effects of alfentanil, however, persisted throughout the 60-min recovery period. Infusion of GI 87084B at lower dose rates (0.001-0.3 nmol/kg/min) in barbiturate-anesthetized dogs showed a threshold dose of 0.1 to 0.3 nmol/kg/min for effects on hemodynamic variables. After infusing 0.3 nmol/kg/min of GI 87084B for 10 min, hemodynamic variables recovered rapidly (10-20 min). Boli of GI 87084B (0.3-100 nmol/kg i.v.) produced dose-dependent decreases in the same hemodynamic variables. The duration of these effects increased from 5 to 20 min at 3 nmol/kg to 15 to 45 min at 100 nmol/kg. Naloxone (0.063 mg/kg/hr) decreased the magnitude and duration of the effects of GI 87084B, suggesting that these effects are mediated through opioid receptors. In summary, GI 87084B produced hemodynamic effects consistent with mu-opioid agonism when administered by infusion or bolus, but these effects were brief in duration compared to other opioids.

Alfentanil↗