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PubMed2002

Dissociation between hemodynamic changes and symptom improvement in patients with advanced congestive heart failure.

BACKGROUND: Changes in hemodynamic measures often serve as surrogate end points in efficacy trials for advanced heart failure, although there are few objective data to support this practice. AIMS: We compared changes in hemodynamic variables vs. changes in symptoms of decompensated heart failure in patients enrolled in a randomized trial. METHODS: We studied 201 patients with New York Heart Association (NYHA) class IIIb or IV heart failure and ejection fraction < or = 25% for > or = 3 months. Patients underwent continuous monitoring by pulmonary-artery catheter during inpatient drug administration. We assessed the relations of changes in hemodynamic variables (baseline minus final measure) to changes at 2 weeks in congestive heart failure symptoms, NYHA class, Yale Dyspnea-Fatigue Index (YDFI) score, and distance achieved in a 6-min walk. RESULTS: No hemodynamic measure significantly predicted either symptom score or NYHA classification. Mean pulmonary artery pressure and pulmonary capillary wedge pressure did show some relation to change in YDFI score in univariable, but not multivariable, analysis. No hemodynamic measure correlated significantly with changes in distance achieved in the 6-min walk test. CONCLUSION: We noted no significant association between improved hemodynamics and improved symptoms in patients with advanced heart failure. Other measures may need to be evaluated as surrogate end points in future trials.

Aged↗
PubMed2001

Quantification of morphologic and hemodynamic severity of coarctation of the aorta by magnetic resonance imaging.

OBJECTIVE: As the morpholgic severity of coarctation of the aorta is difficult to assess, especially after previous repair, the value of the technique of multiplanar reconstruction of magnetic resonance imaging data to achieve a 3-dimensional reconstruction of the aortic arch was evaluated and compared to hemodynamic measurements. METHODS AND RESULTS: We performed 30 examinations in 27 patients aged from 6 to 54 years, with a mean of 21 years, by magnetic resonance imaging using a 1.5Tesla scanner with a standard body coil. Measurements of flow across the coarctation were performed using phase shift velocity mapping, and peak velocity was calculated at the site of stenosis. Aortic cross-sectional area before, at, and beyond the stenosis was reconstructed 3-dimensionally to calculate a percentage degree of stenosis. Morphologic severity of stenosis was correlated to invasively assessed hemodynamic gradients and morphologic data from biplane angiography in 23 patients. Among the 30 examinations, 24 patients had been previously treated by either surgery, in 17 patients, or balloon dilation, while 6 had native coarctation. 3-dimensional reconstruction was possible in all and better delineated the anatomy concerning the hemodynamic relevance of stenoses even as compared with biplane angiography. The correlation between severity of narrowing assessed by diameter measurements in the biplane angiography and 2-dimensional magnetic resonance imaging was r = 0.94, and multiplanar reformation with 2-dimensional magnetic resonance imaging was r = 0.87 with a tendency of higher grading with the 3-dimensional technique (p = 0.0001). The correlation of 2-dimensional magnetic resonance imaging with invasively measured hemodynamic gradients was r = 0.67 versus r = 0.74 for the areas assessed by multiplanar reformation, indicating that the hemodynamic relevance of a morphological approach to evaluate the degree of a stenosis should better be assessed 3-dimensionally. CONCLUSIONS: The 3-dimensional reconstruction of the morphologic severity of coarctation offers additional information over conventional imaging especially in patients with kinking, complex geometry, or collaterals, in whom hemodynamic measurements can become unreliable.

Adolescent↗
PubMed1995

Peritoneal dialysis solutions reverse the hemodynamic effects of nitric oxide synthesis inhibitors.

Nitric oxide (NO) synthesis is inhibited by a variety of L-arginine analogs including NG-nitro-L-arginine methyl ester (L-NAME) and NG NG-dimethylarginine (ADMA). ADMA is present in elevated concentrations in renal failure and potentially could alter microcirculatory hemodynamics during peritoneal dialysis (PD). This investigation utilized the techniques of intravital microscopy to quantitate the mesenteric arteriolar hemodynamic effects of PD solutions during NO synthesis inhibition. L-NAME (100 microns) produced maximum arteriolar vasoconstriction to 74% of baseline diameter (19.9 +/- 2.2 vs. 26.9 +/- 1.4 microns, P < 0.001, N = 10) and ADMA (100 microns) to 68% (20.5 +/- 2.5 vs. 30.1 +/- 2.0 microns, P < 0.01, N = 6). L-NAME decreased red blood cell velocity to 44% of baseline velocity (3.8 +/- 0.8 vs. 8.5 +/- 1.1 mm/second, P < 0.001) and ADMA to 52% (5.1 +/- 1.1 vs. 9.8 +/- 0.9 mm/second, P < 0.01, N = 6). Despite NO synthesis inhibition, standard PD solutions reversed these hemodynamic effects with both 1.5% and 4.25% Dianeal (Baxter) rapidly reversing the vasoconstriction and restoring blood flow back to baseline values. When Dianeal and L-NAME were simultaneously superfused, no L-NAME induced vasoconstriction occurred and Dianeal maintained vasodilatory properties despite L-NAME (P < 0.01, N = 5). This investigation reaffirms that basal levels of NO are important in maintaining normal hemodynamics in the mesenteric microcirculation. Reversal of the L-NAME induced arteriolar hemodynamic effects by Dianeal suggests that the endogenous NO synthesis inhibitor ADMA has no significant effects in the regulation of the mesenteric microvascular arteriolar hemodynamics during PD. Since these PD solutions remain vasoactive despite NO synthesis inhibition, this suggests that these PD solutions possess vasoactive properties primarily through a NO independent mechanism.

Animals↗
PubMed2000

Risk factors for the development of hemodynamically significant cardiac arrhythmias in patients with mechanical ventilation.

PURPOSE: The purpose of this article was to identify the risk factors related to development of hemodynamically significant cardiac arrhythmias in patients with mechanical ventilation. MATERIALS AND METHODS: Holter recording and echocardiogram were performed within 24 hours of ventilator initiation in patients on mechanical ventilation (MV) owing to respiratory failure (RF) from various reasons. RESULTS: From 68 patients, hemodynamically significant cardiac arrhythmias were detected in 18 patients (26.5%). Initial mean arterial pressure, maximal heart rate, and initial pH were identified as risk factors for hemodynamically significant cardiac arrhythmias. Additionally, the patients with pressure-controlled ventilation as an initial ventilatory mode developed hemodynamically significant cardiac arrhythmias less frequently than the patients with other modes (15.8% vs. 40%, P = .03). In multivariate analysis, initial mean arterial pressure (< 70 mm Hg, odds ratio [OR]: 5.5; 95% confidence interval [CI]: 1.2 to 24.2, P = .026), maximal heart rate (> 120/min, OR: 19.7; 95% CI: 2.0 to 190.9, P = .01), and pressure-controlled ventilation (OR: 0.13; 95% CI: 0.03 to 0.55, P = .006) were associated with the development of hemodynamically significant cardiac arrhythmias. CONCLUSIONS: These findings suggest that during the early stages of mechanical ventilation with acute respiratory failure, hemodynamically significant cardiac arrhythmias are directly associated with tachycardia (> or = 120/min), initial MAP (<70 mm Hg), and, inversely, the initial use of pressure-controlled ventilation.

APACHE↗
PubMed2003

Cardiac hepatopathy: clinical, hemodynamic, and histologic characteristics and correlations.

Cardiac hepatopathy, hepatic injury caused by cardiac dysfunction, is a common entity but has been characterized incompletely, particularly the relationship between hemodynamics and histology. We aimed to describe the clinical, biochemical, hemodynamic, and histologic characteristics of this disorder. Eighty-three patients from 2 tertiary referral centers were studied. Patients were divided into 3 groups based on the duration of cardiac dysfunction: (1) acute (n = 12); (2) chronic (n = 53); and (3) acute on chronic (n = 18). Results showed that serum aminotransferase levels were increased typically, particularly in the acute group (median aspartate aminotransferase level was 30.2 times the upper limit of normal [range, 1-100]; P <.0001 vs. the chronic group). The most salient hemodynamic features were elevated right atrial (14 mm Hg [range, 1-29]), and hepatic venous pressures (wedged: 18 mm Hg [range, 5-35]; free: 15 mm Hg [range, 2-30]). The hepatic venous pressure gradient was normal in most (81%), correlated moderately with the aminotransferase levels (aspartate aminotransferase level: r =.59; P <.0001), and associated with the presence of centrilobular necrosis and inflammation, periportal necrosis, and stainable hepatic iron (P <.05 for all comparisons), but not fibrosis. Sinusoidal dilatation was associated with higher right atrial (P =.047) and free hepatic venous pressures (P =.06). Although cirrhosis was rare (n = 1), centrilobular fibrosis was common (74%) and not associated with any hemodynamic measurement. In conclusion, cardiac hepatopathy has diverse clinical, hemodynamic, and histologic manifestations that vary with the temporal course of cardiac dysfunction. Hepatic fibrosis is common, but does not correlate with systemic or hepatic hemodynamics.

Adolescent↗
PubMed1998

Effect of large fundal varices on changes in gastric mucosal hemodynamics after endoscopic variceal ligation.

UNLABELLED: BACKGROUNDS AND STUDY AIMS: Effect of endoscopic variceal ligation (EVL) on gastric mucosal hemodynamics would differ in patients with and without large fundal varices. The aim of this study was to test this hypothesis. PATIENTS AND METHODS: Twenty-seven patients with cirrhosis and large sized esophageal varices were prospectively studied. There were eight patients with large fundal varices and 19 patients without large fundal varices. Before EVL, gastric mucosal hemodynamics were endoscopically assessed by laser-Doppler velocimetry and reflectance spectrophotometry in the antrum and the corpus. In the reflectance spectrophotometric measurements, gastric mucosal hemoglobin content (IHb) and gastric mucosal oxygen saturation (ISO2) were determined. The severity of portal-hypertensive gastropathy (PHG) was also recorded at the antrum and the corpus. For data analysis, PHG was scored (absent, 0; mild, 1; severe, 2; bleeding, 3). These measurements were repeated after initial (three days after initial session) and repeated (seven days after last session) EVL. RESULTS: At the antrum, neither PHG score nor gastric mucosal hemodynamic parameters were modified after initial and repeated EVL in patients with and without large fundal varices. In addition, no significant differences of the integrated changes in PHG score and gastric mucosal hemodynamic parameters were observed in the two groups. At the corpus, PHG score significantly increased after initial and repeated EVL in patients without large fundal varices. In these patients, laser-Doppler signal and ISO2 significantly decreased and IHb significantly increased after initial and repeated EVL. In contrast, PHG score, laser-Doppler signal, and ISO2 did not change significantly in patients with large fundal varices, although IHb transiently increased after initial EVL. Furthermore, the integrated changes in PHG score and gastric mucosal hemodynamic parameters were significantly lower in patients with large fundal varices than in those without. CONCLUSION: The aggravation of PHG after EVL is due to congestion of the gastric mucosal circulation. The presence of large fundal varices plays a protective role in the development of EVL-induced gastric mucosal hemodynamic derangement.

Adult↗
PubMed2000

Changes in hemodynamic parameters and volume homeostasis with the menstrual cycle among women with a history of preeclampsia.

OBJECTIVE: Among women with a history of preeclampsia the prevalence of hemodynamic and clotting disorders is elevated. In this study we tested the hypothesis that the normal cyclic variation in hemodynamic and renal function parameters with the menstrual cycle that is seen among healthy women would be preserved in women with a history of preeclampsia irrespective of whether they had an underlying hemodynamic or clotting disorder. STUDY DESIGN: We compared the hemodynamic and volume cyclic variations during the menstrual cycle among women with a history of preeclampsia (n = 39) with those among healthy parous control women (control group, n = 10). The participants with a history of preeclampsia were subdivided into groups of women with hypertension with or without thrombophilia (hypertension group, n = 10), women with a normotension and a thrombophilic disorder (thrombophilia group, n = 17), and women without either of these abnormalities (symptom-free group, n = 12). We measured > or =5 months post partum, once during the follicular phase of the menstrual cycle (day 5 +/- 2) and once during the luteal phase (day 22 +/- 2), the following variables: body weight and length, mean arterial pressure, heart rate, cardiac output, plasma volume, glomerular filtration rate, effective renal plasma flow, and concentrations of renal volume homeostatic hormones, reproductive hormones, and catecholamines. From the measured data we calculated body mass index, cardiac index, left ventricular work, total peripheral and renal vascular resistances, effective renal blood flow, and renal filtration fraction. RESULTS: The hypertension group differed from the control group in having higher baseline (follicular phase) values for cardiac output, cardiac output, left ventricular work, renal vascular resistance, and atrial natriuretic peptide and norepinephrine levels. The symptom-free group differed from the control group in having a lower baseline plasma volume and higher baseline cardiac output and left ventricular work values. Women in the thrombophilia group were comparable to those in the control group with respect to baseline hemodynamic and renal function variables except for a higher renal vascular work value. In the control group heart rate, plasma volume, effective renal plasma volume, effective renal blood flow, and concentrations of renin-angiotensin-aldosterone system hormones and norepinephrine were increased during the luteal phase with respect to values during the follicular phase, whereas the renal vascular resistance and atrial natriuretic peptide values were decreased. In the three subgroups of women with a history of preeclampsia this cyclic pattern with the menstrual cycle was preserved for most of these parameters. CONCLUSION: Although baseline hemodynamic and volume status among women with a history of preeclampsia differed from that among healthy parous control subjects, the cyclic variation with the menstrual cycle was largely preserved.

Atrial Natriuretic Factor↗
PubMed1991

Laser angioplasty in peripheral vascular disease: symptomatic versus hemodynamic results.

Most early reports on the efficacy of laser angioplasty have used subjective symptoms rather than objective hemodynamic parameters to evaluate clinical results. We reviewed our experience with hot tip laser-assisted balloon angioplasty in 99 occluded or stenotic arterial segments during 80 procedures in 71 patients, ranging from the aortic bifurcation to the tibial-peroneal trunk. Initial failure to successfully recanalize occluded or stenotic segments occurred in 13 instances (16%). Forty-one procedure-related complications occurred in 31 patients (39%). Functional results were evaluated by use of life-table methods on the basis of symptomatic versus hemodynamic improvement. Cumulative patency rates for symptomatic and hemodynamic improvement were 91% and 64% at 1 month, 71% and 48% at 6 months, and 57% and 34% at 1 year, respectively. These data suggest that symptomatic improvement alone gives a misleadingly high estimate of the efficacy of laser angioplasty when compared with more objective hemodynamic criteria (p less than 0.005). Hemodynamic success was more likely in aortoiliac lesions than femoropopliteal lesions (58% vs 18% at 1 year, p less than 0.01). Hemodynamic parameters should be used to evaluate the success of laser angioplasty, which in its present form, is associated with frequent complications and poor long-term success.

Adult↗
PubMed2003

In vivo endoscopic assessment of arterioarterial anastomoses: insight into their hemodynamic function.

OBJECTIVE: To assess endoscopically the hemodynamic function of arterioarterial (AA) anastomoses in twin-twin transfusion syndrome (TTTS) and monochorionic selective intrauterine growth restriction (IUGR). MATERIALS AND METHODS: The videotapes of TTTS and IUGR patients undergoing laser surgery between July 1997 and December 2001 were reviewed for the presence of AA anastomoses. The hemodynamic equator was defined as the site within the AA anastomosis with color flashing. AA anastomoses were classified as having unidirectional flow, having bi-directional flow, or being non-functional, depending on whether the hemodynamic equator reached a returning vein to one, both, or neither twin, respectively. TTTS was classified in stages as previously described. RESULTS: AA anastomoses were present in 35/183 (19.1%) of TTTS and in 12/24 (50%) IUGR patients. Of these, the hemodynamic equator was visible in 8/35 (22.8%) TTTS patients (all in stage III, and mostly in atypical stage III) and in 6/12 (50%) IUGR patients (overall 14/47, 29.8%). Of the 14 patients with a visible hemodynamic equator, 13 (92.8%) AA anastomoses showed unidirectional (9/13, 69.2% from the smaller to the larger twin) flow, and only 1/14 (7.1%) showed bi-directional flow. CONCLUSION: The hemodynamic equator is visible in approximately 30% of patients with AA anastomoses. Within this group, most AA anastomoses behave as functional arteriovenous anastomoses, and the direction of flow can be from the smaller to the larger twin or vice versa. The data suggest a correlation between sonographic findings and placental vascular design, also implying possible interfetal oxygenation differences. Further assessment of the functional behavior of AA anastomoses is warranted to understand the pathophysiology of TTTS and selective IUGR.

Adult↗
PubMed1996

Comparative electrophysiologic and hemodynamic effects of several amide local anesthetic drugs in anesthetized dogs.

Large and equipotent doses of several local anesthetics were administered in a cardiac electrophysiologic model on closed-chest dogs. Five groups of pentobarbital-anesthetized dogs were each given intravenously 16 mg/kg lidocaine, 12 mg/kg mepivacaine, 4 mg/kg or 8 mg/kg etidocaine, and 4 mg/kg bupivacaine. Lidocaine induced bradycardia, slowing of atrioventricular node conduction (AH), and marked hemodynamic depression, represented by a decrease in mean aortic pressure (MAoP), in the peak of first derivative of left ventricular pressure (LVdP/dt(max)) and by an increase in left ventricular end-diastolic pressure (LVEDP). Atrial pacing at pacing cycle length (PCL) of 298 ms did not enhance the alteration of variables of ventricular conduction (His ventricle [HV] interval and QRS duration). Mepivacaine induced slight alteration of electrophysiologic variables. Atrial pacing at PCL of 312 ms did not enhance the alteration of HV and QRS duration. Mepivacaine induced transient hemodynamic depression. Etidocaine (4 mg/kg) induced electrophysiologic and hemodynamic alterations similar to mepivacaine but artrial pacing at PCL of 330 ms enhanced HV lengthening and QRS widening (P < 0.05). Etidocaine (8 mg/kg) induced marked impairment of PR, HV, QRS, and QT, and dramatic hemodynamic depression represented by a decrease in MAoP from 123.5 +/- 16.2 at baseline to 36.5 +/- 8.3 mm Hg at 1 min (P < 0.001) and of LVdP/dtmax) from 1446 +/- 379 to 333 +/- 93 mm Hg/s (P < 0.001). Bupivacaine induced dramatic impairment of electrophysiologic variables. Bupivacaine also decreased LVDP/dtmax (from 1333 +/- 347 to 617 +/- 299,P < 0.001) and increased LVEDP. We conclude that mepivacaine induced moderate cardiotoxicity. In contrast, lidocaine induced dramatic hemodynamic depression while etidocaine and bupivacaine markedly impaired both electrophysiologic and hemodynamic variables. This double impairment could explain the great difficulty in resuscitating patients who have had cardiotoxic accidents induced by etidocaine or bupivacaine.

Amides↗
PubMed1998

The influence of scalp infiltration with bupivacaine on hemodynamics and postoperative pain in adult patients undergoing craniotomy.

UNLABELLED: After craniotomy, hypertension may contribute to intracerebral hemorrhage. We studied whether scalp infiltration with bupivacaine during craniotomy reduces postoperative pain and hypertension. In a double-blind fashion, 36 adult patients (ASA physical status II or III) undergoing elective craniotomy were randomly assigned to receive scalp infiltration with either bupivacaine (0.25%) and epinephrine (1:200,000) or saline/ epinephrine (1:200,000) for skeletal fixation, skin incision, and wound closure. Heart rate (HR) and mean arterial pressure (MAP) were measured after anesthesia induction, after skull-pin insertion, after scalp infiltration, during dural closure, during skin closure, on admission to postanesthesia care unit (PACU), and 1 h after admission. Visual analog pain scores were recorded in the PACU. MAP was significantly greater in the saline group at scalp infiltration. HR was significantly faster in the saline group at dural and skin closure. The bupivacaine group reported significantly less pain than the saline group at PACU admission and 1 h after admission. Pain scores did not correlate with hemodynamic measurements. We conclude that scalp infiltration with 0.25% bupivacaine with 1:200,000 epinephrine blunts certain intraoperative hemodynamic responses and reduces postoperative pain but has no effect on postoperative hemodynamics. IMPLICATIONS: We sought to evaluate whether scalp infiltration with bupivacaine and epinephrine at the beginning and end of craniotomy would afford more intra- and postoperative hemodynamic stability and influence immediate postoperative pain. We found that intraoperative hemodynamics were not influenced greatly; however, craniotomy patients do have significant postoperative pain, which does not seem to have an influence on hemodynamics in the postanesthesia care unit.

Adolescent↗
PubMed1999

Intraoperative hemodynamic predictors of mortality, stroke, and myocardial infarction after coronary artery bypass surgery.

UNLABELLED: Evidence that intraoperative hemodynamic abnormalities influence outcome is limited. The purpose of this study was to determine whether intraoperative hemodynamic abnormalities were associated with mortality, stroke, or perioperative myocardial infarction (PMI) in a large cohort of patients undergoing coronary artery bypass grafting. Risk factors and outcomes were queried from a state-mandated cardiac surgery reporting system at two hospitals in New York, NY. Intraoperative hemodynamic abnormalities were derived from computerized anesthesia records by assessing the duration of exposure to moderate or severe extremes of hemodynamic variables. Multivariate logistic regression identified independent predictors of perioperative mortality, stroke, and PMI. Among 2149 patients, there were 50 mortalities, 51 strokes, and 85 PMIs. In the precardiopulmonary bypass (pre-CPB) period, pulmonary hypertension was a predictor of mortality (odds ratio [OR] 2.1, P = 0.029), and bradycardia and tachycardia were predictors of PMI (OR 2.9, P = 0.007 and OR 2.0, P = 0.028, respectively). During CPB, hypotension was a predictor of mortality (OR 1.3, P = 0.025). Post-CPB, tachycardia was a predictor of mortality (OR 3.1, P = 0.001), diastolic arterial hypertension was a predictor of stroke (OR 5.4, P = 0.012), and pulmonary hypertension was a predictor of PMI (OR 7.0, P < 0.001). Increased pulmonary arterial diastolic pressure post-CPB was a predictor of mortality (OR 1.2, P = 0.004), stroke (OR 3.9, P = 0.002), and PMI (OR 2.2, P = 0.001). Rapid intraoperative variations in blood pressure and heart rate were not independent predictors of these outcomes. These findings demonstrate the prognostic significance of intraoperative hemodynamic abnormalities, including data from pulmonary artery catheterization, to adverse postoperative outcomes. It is not known whether interventions to control these variables would improve outcome. IMPLICATIONS: Intraoperative hemodynamic abnormalities, including pulmonary hypertension, hypotension during cardiopulmonary bypass, and postcardiopulmonary bypass pulmonary diastolic hypertension, were independently associated with mortality, stroke, and perioperative myocardial infarction over and above the effects of other preoperative risk factors.

Blood Pressure↗
PubMed1981

Hemodynamic changes during fentanyl--oxygen anesthesia for aortocoronary bypass operation.

Fentanyl in doses of 50-60 microgram/kg has been reported to produce anesthesia with remarkable hemodynamic stability in patients with coronary artery disease (CAD). Because the authors had observed hypertension and tachycardia in response to noxious stimulation during aortocoronary bypass (ACB) operations in patients so anesthetized, they studied the hemodynamic changes and anesthetic conditions produced by fentanyl/O2/relaxant anesthesia in patients undergoing elective ACB. Twelve patients with left ventricular (LV) ejection fractions greater than 0.4 were maintained on propranolol until 10 hours before operation and were premedicated with fentanyl, diazepam, and scopolamine. Cannulae were inserted before the study commenced for measurement of intravascular pressures, arterial blood gases, and thermodilution cardiac output. The patients breathed 100 per cent oxygen throughout the study. Controlled ventilation aided by succinylcholine to reduce truncal rigidity maintained PaCO2 at 30-45 torr. Measurements were made after each of the following: breathing oxygen (control), 10 microgram/kg fentanyl, 50 microgram/kg fentanyl, and 0.1 mg/kg pancuronium, tracheal intubation, skin incision, and sternotomy. Fentanyl alone produced no significant hemodynamic changes. Fentanyl and pancuronium in combination produced increased heart rate and reduced stroke volume. Significant and progressively greater increases in mean arterial pressure and systemic vascular resistance followed intubation, skin incision, and sternotomy. Chest rigidity occurred in every patient at a lower fentanyl dose than did unresponsiveness. While fentanyl, 62.4 +/- 2.9 microgram/kg (SE), produced minor hemodynamic changes, it failed to block hemodynamic responses to noxious stimulation. Such changes resulted in increased cardiac work, and could have affected myocardial oxygen balance unfavorably. In eight of the 12 patients, following the last set of measurements, supplementary anesthetic agents were required to maintain hemodynamic stability during the surgical procedure. The authors suggest that this fentanyl/O2/relaxant technique should be modified for patients with severe CAD and reasonably good LV function.

Blood Pressure↗
PubMed1984

Influence of propranolol plasma levels on hemodynamics during coronary artery bypass surgery.

Hemodynamic effects of propranolol during coronary artery surgery were investigated in 26 patients who chronically took propranolol and who received a standardized morphine/diazepam/pancuronium/halothane anesthetic. Effects were shown by correlating logarithm of the plasma propranolol concentrations versus percentage change in hemodynamics following stressful events (induction, intubation, skin incision, sternotomy, and sternal retraction). Log propranolol and hemodynamics following cardiopulmonary bypass also were correlated. A broad range of propranolol levels were observed. Levels (range and mean +/- SD) were preinduction 0-96 (25.6 +/- 21.6) ng/ml; preincision 0-86 (27.2 +/- 24.4) ng/ml; and sternal retraction 0-92 (28.2 +/- 25.4) ng/ml. The range of hemodynamic responses to stressful events also was broad. Representative changes between preincision control and sternotomy were (range and mean +/- SD): HR-8-30 (7 +/- 10) beats/min; PCWP 1-21 (8.5 +/- 4.6) mmHg; CI -0.2-1.1 (-0.2 +/- 0.7) 1 X min-1 X m-2, and SVR -244-1,288 (310 +/- 388) dyn X s X cm-3. By the time of sternal retraction, CI had declined from preincision values in 14 patients. Linear regression analysis demonstrated an inverse correlation between log propranolol and magnitude of HR, MAP, PCWP, and CI response to stressful stimulation. A direct but statistically weaker correlation with SVR also was seen. Significant correlations between log propranolol versus hemodynamic response to anesthetic induction and versus postcardiopulmonary bypass hemodynamics were not observed.

Adult↗
PubMed1988

Hemodynamic effects of doxacurium chloride in patients receiving oxygen sufentanil anesthesia for coronary artery bypass grafting or valve replacement.

Doxacurium chloride is an investigational long-acting neuromuscular blocking drug, which has been shown to be devoid of cardiovascular side effects when administered in modest doses to healthy patients. This is the first hemodynamic study of doxacurium in adult patients with cardiac disease. Forty-one patients scheduled to undergo cardiac surgery were studied. Anesthesia consisted of induction with midazolam 0.2-0.3 mg/kg and sufentanil 0.01-0.03 mg followed by an infusion of sufentanil at 0.03-0.06 mg.min-1. Baseline hemodynamic data were collected during a stable state of sufentanil anesthesia. Doxacurium was then administered in doses of 1, 2, or 3 times its ED95 of 0.025 mg/kg. Hemodynamic measurements were repeated at 2, 5, and 10 min after doxacurium injection in the absence of surgical stimulation. An additional group of control patients received saline instead of doxacurium. Baseline hemodynamic measurements were similar among groups. There was a slight decrease in heart rate in all groups over time. However, there was no significant difference between the groups of patients receiving doxacurium and the control group in which the heart rate decreased progressively from 52 beats/min at baseline to 49 beats/min 10 min after doxacurium administration. At no time was there any significant change in mean arterial pressure, right atrial pressure, or cardiac output. Likewise derived hemodynamic variables including cardiac index, stroke volume, and pulmonary vascular resistance were unchanged. In addition to the decrease in heart rate, the hemodynamic changes, which reached statistical significance, were clinically insignificant and occurred predominantly in the group of patients receiving doxacurium 0.08 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1996

Transesophageal atrial pacing in anesthetized patients with coronary artery disease. Hemodynamic benefits versus risk of myocardial ischemia.

BACKGROUND: Transesophageal atrial pacing (TEAP) provides prompt and precise control of heart rate and improves hemodynamics in anesthetized patients with bradycardia and hypotension. The authors' purpose in this study was to examine the hemodynamic benefits of TEAP versus the risk of myocardial ischemia in patients about to undergo coronary artery bypass surgery. METHODS: Hemodynamics, ventricular filling pressures, mixed venous oxygen saturation, and end-diastolic, end-systolic, and fractional area change of the left ventricle, determined by transesophageal echocardiography (TEE), were measured after anesthesia induction with 30 micrograms/kg fentanyl and at incremental TEAP rates of 65, 70, 80, and 90 beats/min (bpm) in 40 adult patients. Monitoring for myocardial ischemia was accomplished with 12-lead electrocardiograms and biplane TEE assessment of left ventricular regional wall motion. Hemodynamics, electrocardiograms, and TEE measurements at each TEAP rate were compared with baseline awake measurements (except TEE) and with measurements obtained after anesthesia induction before TEAP. RESULTS: Sinus bradycardia occurred in 15 patients after anesthesia induction and was associated with a hypotensive response and a decrease in cardiac output in 10 patients. In these patients, TEAP restored diastolic blood pressure and cardiac output to baseline values at TEAP rates of 65 and 80 bpm, respectively. Stroke volume was similar to baseline measurements after anesthesia induction and at TEAP rates of 65, 70, and 80 bpm, but was significantly reduced from baseline at TEAP 90 bpm. Myocardial ischemia was detected in 7 and 5 patients at a TEAP rate of 80 and 90 bpm, respectively. CONCLUSIONS: Control of heart rate with TEAP restores intraoperative hemodynamics to baseline in patients in whom bradycardia and a hypotensive response develop before coronary artery bypass surgery. When using TEAP for patients with severe coronary artery disease, these results support using the lowest TEAP rate titrated to achieve optimal hemodynamics, while closely monitoring for myocardial ischemia, especially at TEAP rates > 80 bpm.

Adult↗
PubMed2001

Central and peripheral adverse hemodynamic changes during laparoscopic surgery and their reversal with a novel intermittent sequential pneumatic compression device.

OBJECTIVE: To study the influence of a novel intermittent sequential pneumatic compression device (Lympha-press) on the adverse cardiac and peripheral hemodynamic changes induced by positive-pressure pneumoperitoneum (PPPn) in laparoscopic surgery. SUMMARY BACKGROUND DATA: Creation of PPPn is known to cause adverse central and peripheral hemodynamic changes. An intrasubject observational study was undertaken to quantitate these adverse changes and to assess the influence of an intermittent sequential pneumatic compression system on these adverse hemodynamic changes during laparoscopic surgery with PPPn. METHODS: The study involved 16 consecutive patients undergoing laparoscopic surgery with PPPn of 12 mmHg and 30 degrees head-up tilt position. The following peripheral hemodynamic recordings were made using Doppler ultrasound: peak systolic velocity (PSV), end diastolic velocity (EDV), and cross-sectional area of the femoral vein. Central monitoring included cardiac output and stroke volume by transesophageal Doppler, blood pressure, and pulse. The hemodynamic state based on these parameters was assessed before induction of PPPn with the anesthetized patient in the supine position, after induction of PPPn and head-up tilt position with Lympha-press off, and during PPPn and head-up tilt position with Lympha-press on, and after desufflation with the patient in the supine position under general anesthesia. RESULTS: Positive-pressure pneumoperitoneum and the head-up tilt position resulted in a 33% reduction in PSV, a 21% reduction in EDV, and a 29% increase in cross-sectional area of the femoral vein. This was associated with a 20% reduction in cardiac output and an 18% reduction in stroke volume. Activation of Lympha-press during PPPn and the head-up tilt position resulted in a 129% increase in PSV and a 55% increase in EDV by 55%. It also increased the cardiac output by 27% and stroke volume by 16%, with no effect on cross-sectional area. Compared with the pre-PPPn stage, there was no difference in cardiac output or stroke volume, but the PSV was higher by 78% and the EDV by 32%. After abdominal desufflation in the supine position, the cardiac output and stroke volume were restored to the pre-PPPn level, but persistent and significant elevations were observed during the period of study in PSV, EDV, and cross-sectional area. CONCLUSIONS: Significant and individually variable central and peripheral hemodynamic changes are encountered during laparoscopic surgery with PPPn and the head-up tilt position. These are reversed by intermittent sequential pneumatic compression using Lympha-press.

Adult↗
PubMed1993

Dobutamine infusions in stable, critically ill children: pharmacokinetics and hemodynamic actions.

OBJECTIVE: To delineate dobutamine pharmacokinetics and hemodynamic responses in children. DESIGN: Prospective, pharmacokinetic study using sequential, graded dosing of drug. INTERVENTIONS: Graded intravenous dobutamine infusions of 0.5, 2.5, 5, 10, and 20 micrograms/kg/min were sequentially administered for 25 mins each. Plasma dobutamine concentrations and echocardiographically determined hemodynamic data were obtained at baseline and at 15 and 25 mins during each infusion rate. Hemodynamic responses were evaluated by paired t-test and by computerized evaluation of individual dose-response curves. SETTING: Pediatric intensive care unit in a university setting. PATIENTS: Eleven stable, critically ill children previously requiring inotropic support with dobutamine. Seven patients were postcardiac surgical patients; four patients had acute cardiac dysfunction with septic shock and/or adult respiratory distress syndrome. MEASUREMENTS AND MAIN RESULTS: Mean cardiac index increased from 3.8 to 5.2 L/min/m2 (p < .05). Increasing the infusion rate from 10 to 20 micrograms/kg/min increased cardiac index by 16% (p < .05). Cardiac index increased by > 10% in four of seven patients at a dobutamine infusion rate of 0.5 microgram/kg/min (mean 21%). The relationship of plasma dobutamine concentration to cardiac index, systolic blood pressure, and heart rate fit a threshold model with a log-linear relationship after the threshold in seven of nine, seven of 11, and eight of 11 patients, respectively. As anticipated, in the patients who responded, there were linear increases in hemodynamic responses with exponential increases in plasma dobutamine concentrations. Mean plasma clearance rate was 82 +/- 3 mL/min/kg. First-order kinetics were demonstrated by the direct linear relationship of plasma dobutamine concentration to infusion rate (mean r2 = .95; p < .01 for each patient) and by independence of clearance from dose and duration of each infusion. CONCLUSIONS: Dobutamine effectively improves systolic function in critically ill children. Hemodynamic responses to dobutamine generally follow a predicted log-linear dose-response model. Dobutamine clearance in this study was consistent with first-order kinetics. The wide variability in hemodynamic responses and clearance kinetics indicate that dobutamine infusions must be titrated individually.

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