Peripheral Resistance Index Research Articles

Maintenance of Minute Circulation Volume during Orthotopic Liver Transplantation

Objective: to optimize procedures to maintain minute circulation volume at different stages of orthotopic liver transplantation. Subjects and methods. In the period 2005—2010, Sverdlovsk Regional Clinical Hospital One performed 32 orthotopic liver transplantations, including one retransplantation. The patients’ ASA class was (4—5). The operations were carried out under general anesthesia. The mean duration of surgery was 8.1 (range 5.8—10.5) hours. The investigators applied anesthesia based on iso-fluorane 0.6—0.9 MAC (by monitoring the anesthesia depth index with cerebral state index (CSI-40-60)), as well as extended central hemodynamic monitoring (prepulmonary hemodilution). All the operations were made via portofemoroaxillary bypass, by using a centrifugal Biopump. Eight surgical stages were identified: 1) run-in (after tracheal intubation); 2) liver mobilization; 3) partial bypass; 4) complete bypass (hepatectomy, a liver-free period); 5) reperfusion; 6) a postreperfusion period (bypass end); 7) biliary repair; 8) the end of an operation. The concentrations of blood parameters, electrolytes, acid-base balance, and the levels of lactate and glucose were examined. The data were processed statistically. Central hemodynamics was monitored by prepulmonary thermodilution, by calculating cardiac index (CI), stroke index, and total peripheral vascular resistance index (TPVRI) at the stages: liver mobilization, postreperfusion period (bypass end), and the end of surgery. Results. Even during partial bypass, there was a significant drop in mean blood pressure (MBP) as compared to the baseline levels (p<0.05). Reperfusion was also accompanied by a significant decrease in MBP and an increase in heart rate. At the end of reperfusion and in the postreperfusion period, TPVRI was halved (689.2±68.0) as compared to the baseline levels. In the postreperfusion period, central venous and pulmonary artery pressures were significantly increased by 32 and 21%, respectively. That period was marked by a significant rise in CI. Serum lactate and glucose elevations starting from the complete bypass stage were associated with the liver being excluded from the circulation and cannot be a marker of inadequate tissue perfusion. Conclusion. The decrease in MBP during portofemoroaxillary bypass is associated with hypovolemia and mainly with vasoplegia during reperfusion. Approaches to maintaining the adequate minute circulation volume depend on the surgical stage: sufficient preload is needed during complete bypass and it is expedient to combine an infused load with vasopressors for the correction of the reperfusion syndrome with low TPVR. Key words: liver transplantation, minute circulation volume, general anesthesia, central hemodynamics.

Cutaneous blood flow and peripheral resistance in type II diabetes as compared to intermittent claudication patients

Insulin deficient, type I diabetic patients have reduced skin blood flow reserve. It is not known whether these skin perfusion abnormalities also exist in non-insulin dependent (type II) diabetic patients. An additional open question is whether the reduced skin blood flow is due to increased resistance of the cutaneous microvasculature or to decreased peripheral perfusion pressure due to increased atherosclerosis in the diabetic population. We measured skin blood flow by laser Doppler flowmetry in patients with type II non-insulin treated diabetes. Limb systolic blood pressure was measured distally using a sensitive sonar Doppler device at the finger and toe. The ratio of pressure to flow was computed as an index of peripheral blood flow resistance. To assess the effect of cutaneous blood flow resistance, we elicited maximal vasodilation by increasing local skin temperature directly at the site of the laser Doppler probe. We compared blood flow and pressure in diabetic patients with the values in non-diabetic control patients. As a further control population, we also assessed these same parameters in non-diabetic patients with peripheral vascular disease, which may be expected to decrease large arterial blood flow pressure without directly affecting the microvasculature. There were 68 type II diabetic patients, 18 non-diabetic control subjects, and 25 non-diabetic patients with intermittent claudication. We measured skin blood flow at the dorsal surfaces of the finger and toe, sites with primarily nutritive capillary perfusion, and at the plantar surfaces of the finger and toe, where arteriovenous shunt perfusion predominates. Heat stimulated flow was markedly lower for the diabetic patients at the finger dorsal surface (16.5 ± 1.4 ml/min/100 g vs 29.8 ± 4.4 ml/min/100 g in the non-diabetic group (p < 0.05). The resistance index was 13.2 ± 1.9 in the diabetic patients and 6.8 ± 1.7 in the controls (p < 0.05). At the toe dorsum, basal temperature flow was significantly lower in the diabetic group (0.6 ± 0.1 ml/min/100 g) than in the non diabetic group (1.1 ± 0.2 ml/min/100 gm) with resistance index almost twice as high (379 ± 32) in the diabetic group versus non-diabetic controls (208 ± 36) [p < 0.01 for both comparisons]. With the local application of heat, there was a much larger increase in flow in the non-diabetic subjects than in the diabetic group. The resistance index dropped much more with heat stimulation for the non-diabetic patients (10.8 ± 3.3) than for the diabetic patients (50.6 ± 10.4) [p < 0.01] There was a lesser rise in flow at the toe pulp surface with heat in the diabetic patients (31.3 ± 3.0 ml/min/199 gm) than in the control subjects (45.4 ± 5.9 ml/min/100 gm; p < 0.05) with a higher resistance index (13 ± 4) than in the non-diabetic subjects (4 ± 1) [p < 0.05]. The claudication patients had substantially greater flow at the toe dorsal surface at basal temperature (2.2 ± 0.4 ml/min/100 gm) with significantly lower resistance index (126 ± 24) than the non-diabetic controls (p < 0.05). At 44°C, toe dorsum flow was significantly higher (17.8 ± 3.7 ml/min/100 gm) than in the diabetic patients with lower resistance index (17.0 ± 6.6) [p < 0.05]. Toe pulp flow at basal temperature was significantly higher (10.1 ± 2.0 ml/min/100 gm) than in either the diabetic (3.8 ± 0.6) or non-diabetic control groups (3.5 ± 1.4) [p < 0.05]. Skin blood flow is impaired in diabetes. The reduction is due to increased resistance in the capillary bed rather than to reduced perfusion pressure. The increased resistance was found only in the diabetic patients, not in the non-diabetic patients with peripheral vascular disease. To the contrary, there appeared to be a compensatory decrease in skin flow resistance in the patients with peripheral vascular disease. Thus, there is a small vessel disease which impairs cutaneous perfusion in diabetes, but there is no such effect on skin blood flow in non-diabetic patients with large vessel disease.

The influence of tocolytic drugs on cardiac function, large arteries, and resistance vessels

Beta-2 adrenoceptor agonistic drugs like ritodrine have been the reference tocolytic drugs, but are associated with cardiovascular side-effects. Atosiban, a newer drug, is a competitive antagonist of oxytocin and has been claimed to have fewer cardiovascular side effects. Until now, there has mainly been a subjective reporting of adverse reactions and few objective cardiovascular data. Evaluation of the acute effects of therapeutic doses of ritodrine and atosiban compared with placebo on cardiac function, large artery properties, blood pressure, and resistance vessels. A double-blind, randomized trial was carried out in 20 non-pregnant female volunteers. Hemodynamic measurements were made under standardized conditions during kinetic steady state. Cardiac output was measured with echocardiography, large artery properties with an echo-tracking device. The effect on the microcirculation was estimated using the total peripheral resistance index (TPRI). Atosiban did not differ from placebo. With ritodrine, cardiac function increased by 79% compared with placebo because of a rise in heart rate (91%). TPRI decreased by 48%. Ritodrine increased the distensibility of the common carotid artery by 62% and the compliance by 83%, independent of blood pressure. Compliance of the common femoral artery increased independently of pressure by 33% and the distensibility by 59%. Aortic pulse wave velocity was not influenced by either medication. The present study shows potential beneficial vascular effects of ritodrine that are counterbalanced by the cardiac effects. Atosiban has no clinically relevant cardiovascular effects and may be a good alternative for ritodrine in pregnant women at risk of cardiovascular complications.

Changes in Skin and Subcutaneous Perfusion in Very-Low-Birth-Weight Infants during the Transitional Period

Background: Conventional parameters of circulation that are routinely used in neonatal intensive care units, including blood pressure, have been reported to be inadequate in improving prognosis of very-low-birth-weight (VLBW) infants. Recently, the importance of evaluating the blood flow to each organ, including both vital and nonvital organs, has been increasingly recognized. Objectives: To study the changes in peripheral perfusion occurring in VLBW infants of less than 32 weeks’ gestation during the extrauterine transitional period. Methods: In 32 VLBW infants of less than 32 weeks’ gestation, forehead blood flow (FBF) and lower-limb blood flow (LBF) were measured for 48 h after birth using a novel laser Doppler flowmeter, and the indices of vascular resistance were estimated. Superior vena cava (SVC) blood flow was measured by echocardiography. Changes in these variables of circulation as well as the correlations were evaluated. Results: Both FBF and LBF significantly increased at 24 h, while the SVC flow remained unchanged over the same period. Both forehead and lower-limb vascular resistance indices significantly decreased at 24 h. LBF was negatively and positively correlated with estimated upper body vascular resistance and SVC flow, respectively. Conclusions: The increase in the peripheral blood flow along with the decrease in the peripheral vascular resistance indices, without an increase in the systemic blood flow at 24 h of age, indicated vasodilation in skin and subcutaneous tissue during the transitional period in VLBW infants. FBF and LBF can be useful parameters as indicators of both peripheral and systemic circulation.

Morfologia e função cardíacas em pacientes renais crônicos, com ou sem diurese residual, em tratamento hemodialítico

In patients with chronic renal failure on hemodialysis, left ventricular hypertrophy is related to the increase in total peripheral vascular resistance and volume overload. The presence of residual diuresis enables greater control of the volemia of these. We evaluated the morpho-functional changes of the left ventricle in patients with chronic kidney disease on hemodyalisis treatment with and without residual diuresis. A total of 31 non diabetic patients were studied and they were divided into two groups: with residual diuresis (RD+) (n = 17) and without residual diuresis (RD-) (n = 14). In both groups, RD+ vs. RD-, using data from a Doppler echocardiogram differences were found, respectively, in the cardiac index (3.9 ± 0.2 vs. 3.0 ± 0.2 L/min/m²; p = 0.0056), systolic index (54 ± 2.9 vs. 45 ± 3.3 mL/b/m²; p = 0.04), end diastolic volume (141 ± 6.7 vs. 112 ± 7.6 mL; p = 0.008), end diastolic diameter (52 ± 0.7 vs. 48 ± 1.1 mm; p = 0.0072) and total peripheral resistance index (1121 ± 56 vs. 1529 ± 111 dyne.sec.cm-5; p = 0.001). RD+ had lower relative wall thickness than RD- (0.38 ± 0.01 vs. 0.45 ± 0.01; p = 0.0008). The ejection fraction and the left ventricular mass index were similar in both groups. The urinary 24-hour volume correlated with the relative wall thickness (r = -0.42; p = 0.0186) and with peripheral resistance index (r = -0.48; p = 0.0059). In conclusion, there were distinct ventricular geometric patterns and different functional performances between RD+ and RD- groups. The presence of residual diuresis can be responsible by these modifications in systolic function.

The application of pulse indication contour cardiac output to early fluid resuscitation in patients with septic shock

Objective To explore the use of pulse indication contour cardiac output (PiCCO) as a guidance for fluid resuscitation and vasopressors employment in patients with septic shock in order to find out the efficacy of this resuscitation strategy in the respect of outcome of patients. Mtthod A total of 30 patients with septic shock were treated with the EDGT fluid treatment protocol as the conventional treatment group from December 2006 to June 2008; and another 26 patients were given fluid treatment under the guidance of PiCCO as PiCCO group from July 2008 to October 2009. Exclusion criteria included patients with history of heart and lung diseases, and liver and kidney dysfunction. The mean arterial blood pressure was maintained above or equal to 65mmHg in PiCCO group,and fluid resuscitation was concluded when global end-diastolic volume index reached 600～750 mL·-2 with the stroke volume variation in ＜ 10% and without auricular fibrillation. Nor-epinephrine was administrated to adiust the systemic peripheral vascular resistance index during 1300～1500 d·s·cm-5·m-2.Dobutamine was empoyed when global ejection fraction was compromised. The options of liquid and diuretics depend upon the presence d extra-vascular lung water. Central venous oxygen saturation and the level of lactate were observed 6hours after resuscitation. The liquid equilibrium for 3 days and the dosage of vasopressors were also recorded. The rate of survival, the time taken for weaning from mechanical ventilation, the days of ICU stay and rate of intact organ function within 28 days were compared between two groups. Results The demphics of patients of two goups were similar. There were no significant difference between PiCCO and the conventional group in values of central venous oxygen saturation and lactate 6 hours after admission to ICU (P ＞ 0.05). And 6 h and 1d after fluid resuscitation, the dosages of dobutamine and the dosages of nor-epinephrine used in PiCCO group were significantly higher than those in conventional group in which the dosages of dobutamine in two groups were [(145.4±24.5)mg vs. (104.2 ± 46.3) mg and (330.2 ± 30.3) mg vs. (202.4 ± 40.3) mg], respectively, and the dosages of nor-epinephrine [(14.5±3.8) mgvs. (10.2±5.6) mgand (38.2±4.2) rng vs.(20.1±6.2) mg], respectively. However, the dosages of vasopressors were similar between two groups 2 d and 3 d later. The amounts of liquid administered to get equilibrium in 6 h and the 3 d in PiCCO group were significantly less than those in conventional group [(2121±578) mL vs. (2910±987) mL and (3845±435) mL vs. (4545 ± 765) mL and (2467±510) mLvs. (2867±618) mL and (951±332) mLvs. (1472±533) mL], respectively. The days required to get free from mechanical ventilation within 28d were significantly longer in PiCGO group[(19.7 ± 8.3) d vs.(15.1±9.1) d], but the days of ICU stay were significantly shorter in PiCCO group [(7.5 ± 3.5) d vs. (9.5±3.2) d] (P＜0.05). The rates of survival and days free from organ failure within 28 days of two groups were similar(P＞0.05). Conclusions When the early fluid management guided with PiCCO in septic shock patients,the fluid management can be implement more safely and precisely. It can shorten the days of ICU stay and days of mechanical ventilation support with avoidance of fluid resuscitation. Key words: Septic shock; Pulse indicate Contour Cardiac Output; Fluid management; Mortality

Effects of Acute Normovolemic Anemia on Hemodynamic Parameters and Acid-Base Balance in Dogs

The aim of this study was to evaluate the hemodynamic and acid-base status of dogs subjected to acute normovolemic anemia. The dogs (n = 10) were evaluated 15 minutes and 24 hours after induction of anemia (hematocrit below 18%) with blood withdrawal and simultaneously replacement of same volume of Ringer's lactate solution and hydroxyethyl starch-based solution in a 2 : 1 ratio. The cardiac output was measured by Doppler echocardiography and blood pressure by oscillometric device, and posteriorly hemodynamic parameters were calculated. The anemic groups had increase in cardiac index (P < .05) (3.82 ± 1.05 to 5.86 ± 1.49 and 5.81 ± 1.63 L/min × m2) and decreases (P < .05) in the indices of total peripheral resistance (6797.81 ± 3060.22 to 3220.14 ± 1275.02 and 3887.74 ± 1394.89 dina·seg/cm5 × m2) and oxygen delivery (7942.84 ± 3344.00 to 4021.68 ± 1627.00 and 4430.82 ± 1402.61 mL/min × m2), respectively. There were no significant changes in pH, but PaO2 and SaO2 values were increased, and PaCO2 reduced in anemic dogs (P < .05). Therefore, acute normovolemic anemia can create significant hemodynamic changes and despite some hemogasometric changes, there were no changes in the acid-base status in dogs.

The influence of high-dose simvastatin and diltiazem on myocardium in rabbits: a haemodynamic study

IntroductionSimvastatin and diltiazem are often prescribed together for the treatment of hypercholesterolaemia in patients with hypertension and/or angina pectoris. However, diltiazem, a CYP3A inhibitor, is a well-recognized risk factor of skeletal muscle myopathy. It is not known whether such interaction also affects myocardial efficiency causing haemodynamic changes. The aim of the experiment was to establish the impact of simvastatin co-administered with diltiazem on the haemodynamic parameters after continuous infusion of dopamine.Material and methodsThe experiments were performed on 28 New Zealand white rabbits. The animals were divided into four groups receiving: 0.2% MC – methylcellulose (control group); diltiazem; simvastatin; simvastatin + diltiazem, for 14 days (po). The following haemodynamic parameters were estimated: cardiac output index (CI), heart rate (HR), systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP) and total peripheral resistance index (TPRI). The registration of haemodynamic parameters was performed by the Doppler method and during the experiments the animals were anaesthetized with α-chloralose (75 mg/kg bw) and urethane (500 mg/kg bw).ResultsDopamine did not cause a statistically significant increase in CI in rabbits receiving simvastatin alone. Diltiazem significantly increased CI if given simultaneously with simvastatin, which might suggest the improvement of cardiac efficiency resulting from such interaction.ConclusionsThe possibility of another mechanism of drug-drug interaction than the one based on CYP3A inhibition, and its impact on cardiac or skeletal muscle, might be considered.

Hemodynamic changes as a diagnostic tool in acute heart failure—a pilot study

Objectives To examine whether posturally induced changes in cardiac output differentiate patients presenting with dyspnea to the emergency department (ED) with acute heart failure (AHF) from other causes. Methods This was an observational study of patients presenting to the ED with dyspnea. Exclusion criteria included ischemic chest pain, electrocardiographic changes diagnostic of acute myocardial infarction, pericardial effusion or chest wall deformities causing dyspnea, or heart transplant. Hemodynamic variables of cardiac index (CI), total peripheral resistance index, and thoracic fluid content (TFC) were determined in upright seated and supine positions 3 minutes apart using bioreactance technology (Cheetah Medical Inc, Portland, Ore). Acute heart failure was defined as either B-type natriuretic peptide 100 to 500 pg/mL and discharge diagnosis of AHF or a B-type natriuretic peptide greater than 500 pg/mL. Results Of 92 patients, 25 had AHF, 23 had asthma/chronic obstructive pulmonary disease (COPD), and 44 had dyspnea related to other conditions; 41 (44.1%) were male, 56 (60.2%) were African American, and the mean age was 58 ± 15.0 years. Mean baseline TFC was higher in AHF vs asthma/COPD (59.3 ± 26.0 vs 39.7 ± 14.8 1/kW, P = .003) and trended higher compared to other patients with dyspnea (49.2 ± 22.0, P = .10). Postural changes in mean CI were lower in AHF (−0.20 ± 0.84 L min −1 m −2) vs asthma/COPD (1.20 ± 1.23 L min −1 m −2; P = .002) and other dyspnea patients (0.82 ± 0.91 L min −1 m −2; P = .007). Conclusion Patients with AHF have greater TFC but lower CI responses to postural changes compared to patients with asthma and COPD. Knowledge of these changes may help rapidly differentiate AHF from asthma and COPD in the ED.

Proto-dialytic cardiac function relates to intra-dialytic morbid events

Intra-dialytic morbid events (IDME) such as intra-dialytic hypotension (IDH) and muscle cramps frequently complicate haemodialysis (HD). Cardiac dysfunction is highly prevalent in HD patients. We investigated the relationship between proto-dialytic (i.e. early intra-dialytic) cardiac function and IDME in HD patients. Heart rate, beat-to-beat blood pressure (BP) and cardiac output were continuously measured during the first 30 min of dialysis treatment using the Task Force™ Monitor. Total peripheral resistance index (TPRI) was calculated from cardiac index (CI) and BP. Univariate, multivariate and logistic regression analyses were employed to relate IDME to haemodynamic predictors; Kaplan-Meier method was employed for time-to-event analysis. Fourteen HD patients (age 67 ± 15 years; 7 females) were studied. Dialysis treatment was complicated by IDH and muscle cramps in 4 and 8 out of 30 sessions, respectively. CI was higher in patients without IDME (2.6 ± 0.5 L/min/m(2)) as compared to those with muscle cramps (2.0 ± 0.3 L/min/m(2)) or IDH (1.8 ± 0.2 L/min/m(2); all P < 0.05). CI and TPRI at baseline independently predicted IDME in a multivariate regression analysis (odds ratio: 0.043 per unit of CI, 95% confidence interval: 0.003-0.611; odds ratio: 1.124 per unit of TPRI, 95% confidence interval: 1.25-1.01). Patients were stratified by tertiles of CI. IDME occurred in the two lower tertiles, whereas patients in the upper tertile were event free (log-rank test, P < 0.002). Low CI and high TPRI in the first 30 min of HD are associated with an increased risk of IDME.

Cardiovascular correlates of insulin resistance in normotensive and hypertensive African Americans

Insulin resistance (IR) is associated with obesity and predisposes to diabetes mellitus (DM) and cardiovascular disease. The purpose of this study is to determine if IR is related to cardiovascular function independent of DM or hypertension among African Americans (AA). Four hundred sixty-two nondiabetic AA (50% hypertensive and 51% women) were studied on an inpatient General Clinical Research Center. Measurements included anthropometrics and 24-hour blood pressure (BP), heart rate (HR), fasting blood glucose, plasma aldosterone, and insulin. Stroke volume (SV) and cardiac output (CO) were measured by impedance plethysmography; peripheral vascular resistance (PVRI) and vascular compliance indices (VCI) were computed. These measurements were also obtained in response to mental (computerized math testing) and pharmacologic (graded norepinephrine infusion) stress. Insulin resistance was calculated using the homeostasis model assessment (HOMA-IR). SV, CO, and VCI decreased with increasing HOMA-IR, whereas HR and PVRI increased. Overall, BP, HR, and PVRI were positively correlated with HOMA-IR ( P < .01); and SV index, cardiac index, and VCI were negatively correlated with HOMA-IR ( P < .0001). The correlations persisted after adjustment for BP, age, sex, plasma aldosterone, total cholesterol, or low-density lipoprotein and high-density lipoprotein cholesterol. In addition, multiple linear regression analyses showed that HOMA-IR contributes to the maximum variability of all the hemodynamic variables. Blood pressure responses to math stress and norepinephrine infusion did not correlate with HOMA-IR. Unrelated to DM and BP, IR is associated with increased PVRI and decreased CO in AA. These observations suggest that an exclusive focus on effects of IR on DM or BP may ignore independent pathophysiologic contributions of IR to cardiovascular disease.

Utilization of impedance cardiography in noninvasive assessment of hemodynamic status in cirrhotic patients

This study aimed to assess hemodynamic alterations noninvasively using a dedicated device Task Force® Monitor providing various hemodynamic data utilizing impedance cardiography and beat-to-beat blood pressure analysis via a vascular unloading unit. Forty-seven patients with cirrhosis awaiting hepatic transplantation and 26 healthy volunteers matched for age and gender were enrolled. Basic hemodynamic status of these patients (following temporary interruption of any drugs affecting the cardiovascular system) was evaluated noninvasively by Task Force® Monitor with patients in the supine position. Mean age of the patients was 46 years and 74.5% were male. The etiology of cirrhosis was viral hepatitis in 59.5% and alcoholic cirrhosis in 19.1% of cases, whereas 17% had cryptogenic cirrhosis. 38.3%, 25.5%, and 36.1% of the patients were stratified into groups A, B and C according to the Child-Pugh classification, respectively. Heart rate, cardiac output and cardiac index were significantly higher in patients with cirrhosis compared to the control group. However, diastolic blood pressure, total peripheral resistance and total peripheral resistance index were significantly lower in the cirrhosis group. This situation representing a hyperdynamic circulatory state became more prominent in conjunction with advanced disease severity. The present study demonstrates that the Task Force® Monitor device is capable of delineating the hyperdynamic circulatory state in cirrhotic patients and satisfactorily indicates differences between controls and patients at diverse levels of severity. Regarding potential applications in clinical practice and research, noninvasive hemodynamic monitoring by Task Force® Monitor may be a reliable and reasonable alternative tool to invasive procedures.

Cerebro- and cardiovascular reactivity and neuropsychological performance in hypertensive patients

Background Hypertensive (HT) patients are at higher risk of cognitive decline than normotensive individuals, because high blood pressure is a risk factor for mild cognitive deterioration. In this study cardio- and cerebrovascular reactivity along with cognitive performance was assessed on newly diagnosed HT patients. Methods Diagnosis of hypertension was based on international recommendations. None of the patients had diabetes, and all of them had normal cerebral CT scan. Eighty-one patients (43.5 ± 10.2 years, male/female ratio: 42/39) were compared with 94 healthy controls (44 ± 9.4 years, male/female ratio: 50/44). In both groups continuous, non-invasive and simultaneous monitoring of cerebral and cardiac hemodynamical parameters were recorded during head-up tilt table testing (HUTT). Reaction time, attention and memory skills, anxiety and depression rate were determined by neuropsychological tests. Results During HUTT significant differences were found in certain cardiovascular parameters (blood pressure, total peripheral resistance index, stroke index), but no differences were detected in cerebral blood flow velocity . While there was no significant difference in reaction time between the two groups, tests estimating short-term memory (Digit Span Test) differed significantly. Moreover, sum of standardized test scores was significantly lower, while anxiety level was significantly increased in HT patients compared to controls. Conclusion Decrease in neuropsychological performance along with alterations of cardiovascular parameters is an early manifestation of hypertension. Aim for an early intervention and accurate treatment is crucial for preventing further impairments.

Cardiovascular and Psychological Reactivity and Recovery from Harassment in a Biracial Sample of High and Low Hostile Men and Women

This study emphasizes the importance of studying the emotional, motivational, and cognitive characteristics accompanying and the potential hemodynamic mechanisms underlying cardiovascular reactivity to and recovery from interpersonal conflict. The relation of dispositional hostility to cardiovascular reactivity during a frustrating anagram task and post-task recovery was investigated. The sample was composed of 99 healthy participants (age, 18-30years; 53% women; 51% Caucasian; 49% African American)-half randomly assigned to a harassment condition. High and low hostility groups were created by a median split specific to sex and race subgroup score distributions on the Cook-Medley Hostility Scale. It was hypothesized that hostility would interact with harassment such that harassed, high hostile individuals would display the greatest cardiovascular and emotional reactivity and slowest recovery of the four groups. Participants completed a 10-min baseline, a 6-min anagram task, and a 5-min recovery period with blood pressure, heart rate, pre-ejection period, stroke index, cardiac index, and total peripheral resistance index measured. Harassed participants displayed significantly greater cardiovascular responses and lower positive affect to the task and slower systolic blood pressure (SBP) recovery than did nonharassed participants. The high hostile group, irrespective of harassment, showed blunted cardiovascular responses during the task and delayed SBP recovery than the low hostile group. Although the predicted interaction between hostility and harassment was not supported in the context of cardiovascular responses, such an interaction was observed in the context of blame attributions, whereby harassed hostile participants were found to blame others for their task performance than the other subgroups.

Complex Therapy for Intraoperative Blood Loss during Pelvic Bone Repair

Objective: to introduce blood saving technologies and to develop algorithms for management of patients with pelvic fractures. Subjects and methods. Sixty patients aged 40.6±2.3 years with pelvic fractures were examined. The banking of packed autoerythrocytes and auto freshly frozen plasma (AutoFFP), intraoperative acute hypervolemic hemodilution (AHH), and instrumental reinfusion of washed autoerythrocytes were made in all the patients. Blood loss volume averaged 32.1±1.7 ml/kg. The parameters of central hemodynamics (CH), blood oxygen-transport function, the blood system (red blood cells, hemoglobin, packed cell volume, and platelets) were studied. AutoFFP was transfused in the most traumatic period of surgery, autoblood was on completion of surgical hemostasis, and washed autoerythrocytes were within 3—4 hours after surgery. Postoperative reductions in hemoglobin to below 80 g/l and packed cell volume below 25% are indications for packed autoerythrocyte transfusion. Results. During preoperative autoblood banking, the parameters of CH and the blood system underwent no changes, all variations in the parameters were within the normal range and compensatory. When AHH and instrumental washed erythrocyte reinfusion were conducted, there was a significant increase in cardiac index (CI), stroke index by 37 and 30%, respectively; reductions in total peripheral vascular resistance index by 38%, mean blood pressure by 18%, moderate hypercoagulation, and significant decreases in hemoglobin, packed cell volume, red blood cells by 17, 15, and 18%, respectively. The values of acid-base condition and homeostasis underwent no considerable changes. Arterial blood O2 content was significantly lowered by 16%; however, global O2 uptake remained unchanged at the baseline levels due to the increase of CI by 30% of the baseline level. Conclusion. The application of blood saving technologies, preoperative autoblood banking in particular, AHH, and instrumental washed autoerythrocyte reinfusion allowed a refusal to use allo-geneic blood components during pelvic repair, by preventing the development of hemotransfusion complications. Key words: blood loss, blood saving, packed autoerythrocytes, auto freshly frozen plasma, acute hypervolemic hemodilution, autohemotransfusion, instrumental washed autoerythrocyte reinfusion, spinal epidural anesthesia.

EFFECTS OF VENTRICULAR GEOMETRY ON VENTRICULAR ARTERIAL COUPLING IN ESSENTIAL HYPERTENSION: PP.8.341

Introduction: Echocardiography is used to assess ventrículo-arterial coupling (VAC) determined by the balance between the contractile properties of left ventricle (LV) and the pressure load. However ventricular geometry (VG) and cardiac hypertrophy (LVH) may modulate the VAC in hypertension (HT). Adaptative variations of aortic (Eal) and ventricular (Ees) elastances may be related with VAC changes within normal systolic function (SF). Objective: To characterize non-invasively the interaction between VG and VAC in HT within normal range of SF and VAC. Methods: We evaluated 23 consecutives hypertensive patients, age 53,3 ± 9,8, male 12(52,2%) female 11 (47,8%), SBP 134,78 ± 12,8 mmHg, DBP 82,47 ± 8,21 mmHg, with Doppler Echocardiography (Vivid 7,GE), using simple pulse method modified for the calculation of Ees and the ratio of end systolic pressure to stroke volume for Eal. VAC is the ratio Eal/Ees.Elastances were normalized to 100 g of ventricular mass. The following measurements were also determined: Mesoparietal fractional shortening, normalized systolic stress (MFS/STRESS), left atrial diameter (LA), correlation E/A (E/A), diastolic isovolumic relaxation time (Tau), systolic work index (SWI), systolic volume index (SVI) and peripheral vascular resistance index (PVRI). The VG was classified as: normal (Nor), concentric remodeling (Rem), concentric LVH (Conc) and eccentric LVH (Exc). Results: Significative differences on the VG were found in Nor with Rem: Ees(p < 0,05); Conc: LA(p < 0,01), Eal(p < 0,01), E/A(p < 0,01), SWI(p < 0,05); Exc: SWI(p < 0,05), SVI(p < 0,05), LA(p < 0,05), Eal(p < 0,01). Conclusions: In HT with SF and VAC within normal ranges, VG seems to affect VAC, contractility and ventricular performance. The noninvasive measurement of VG and related VAC, may be useful for diagnostic and therapeutic porpoises in early stages in hypertensive patients.

The hemodynamic effects of medetomidine continuous rate infusions in the dog

ObjectiveTo characterize the hemodynamic effects of continuous rate infusions (CRI) of medetomidine administered at doses ranging from 0 to 3 μg kg−1 hour−1. Study designProspective, blinded, randomized experimental trial. AnimalsSix adult purpose-bred mongrel dogs. MethodsAnesthesia was induced with sevoflurane for placement of arterial and venous catheters. Dogs recovered from anesthesia after which baseline hemodynamic measurements were obtained via lithium dilution cardiac output (CO) determination, with subsequent measurements via pulse power analysis to provide continuous CO determinations. Medetomidine, 1, 2, or 3 μg kg−1 hour−1 or a volume equivalent placebo, was administered via CRI for 60 minutes. Systolic, mean, and diastolic arterial pressure, heart rate (HR), CO and stroke volume were measured and stroke index (SI), cardiac index (CI), total peripheral resistance (TPR), and total peripheral resistance index (TPRI) were calculated at 3, 7, 10, 20, 30, 45, 60, 90, and 120 minutes from the start of the infusion. ResultsIncrease in dose decreased SI by 25%, 19%, and 30%, HR by 33%, 57%, and 60%, CI by 50%, 65%, 70% and increased TPRI by 109%, 235%, and 222% from baseline to the 60-minute measurement for the 1, 2, and 3 μg kg−1 hour−1 doses, respectively. HR, TPRI, and CI all showed significant differences over the duration of the study from the placebo treatment. ConclusionsMedetomidine CRI produces clinically relevant changes in CO, TPR, and HR. The demonstrated decrease in CO is largely because of bradycardia and the degree of cardiovascular depression appears to be dose-dependent. These findings are consistent with previously described hemodynamic changes with single bolus administration of medetomidine. Clinical relevanceLow-dose medetomidine CRIs produce clinically relevant hemodynamic depression at doses as low as 1 μg kg−1 hour−1 and should be used cautiously in dogs.

Ways of Improving the Results of Treatment for Pulmonary Thromboembolism

Objective: to reveal the predictors of clinically significant deterioration of cardiac pump function resulting from alveolar opening maneuver (AOM) (mobilization) made early after extracorporeal circulation during standard cardiosurgery. Subjects and methods. Hemodynamic, clinical, and laboratory parameters were analyzed in 20 cardiosurgical patients who had undergone AOM in the early postperfusion period. The study inclusion criteria were a PaO2/FiO2 ratio of less than 350 mm Hg, a cardiac index (CI) of more than 2.5 l/min/m2, a dosage of dopamine and/or dobutamine of not more than 10 ^g/kg/min, and standard AOM performance (Pmax, 30—35 cm H2O; end-expiratory pressure (PEEP), 13—15 cm H2O). Regression analysis was used to identify the predictors of a clinically significant reduction in CI (less than 2.5 l/min/m2). Results. Before and after AOM, CI was 3.1±0.1 and 2.9±0.1 l/min/m2, respectively (p&gt;0.05); however, CI was less than 2.5 l/min/m2 (2.16±0.09 l/min/m2) in 25% of cases. After AOM, CI values were significantly related to those recorded prior to a respiratory procedure (p=0.039), total peripheral vascular resistance index (TPVRI) (p=0.00039), and intrapulmonary blood shunt fraction (Qs/Qt) (p=0.041). There were no relationships to other recorded and estimated hemodynamic parameters (p&gt;0.1). &#8211; After AOM, CI values were unrelated (p&gt;0.1) to the duration of extracorporeal circulation, the period of myocardial ischemia, and the used dosages of inotropic agents. The predictor of a clinically significant CI reduction after AOM was the only index TPVRI (p=0.00025) recorded before a respiratory procedure. Following AOM, the probability of a significant CI reduction substantially increased (the approximation coefficient R2=0.75) at TPVRI values of 2000 din^sec^cm-5^m2 or more. Conclusion. After AOM performed in the early period after extracorporeal circulation, CI values are related to the baseline level of CI, TPVRI, and Qs/Qt; however, after this procedure only the value of TPVRI is a reliable predictor of clinically significantly depressed cardiac pump function. The risk of persistent car-diodepression is highest at TPVRI values of 2000 din^sec^cm-5^m2 or more. AOM should be carried out early after extra-corporeal circulation in cardiosurgical patients, by making an invasive monitoring that makes it possible to maximally correctly evaluate central hemodynamics, including CI and TPVRI. Key words: alveolar opening maneuver (mobilization), lung recruitment, recruiting maneuver in cardiosurgical patients, central hemodynamics during lung recruitment, cardiodepression during lung recruitment.

Predictors of the Cardiodepressive Effect of Alveolar Opening Maneuver (Mobilization) in Cardiosurgical Patients

Objective : to reveal the predictors of clinically significant deterioration of cardiac pump function resulting from alveolar opening maneuver (AOM) (mobilization) made early after extracorporeal circulation during standard cardiosurgery. Subjects and methods. Hemodynamic, clinical, and laboratory parameters were analyzed in 20 cardiosurgical patients who had undergone AOM in the early postperfusion period. The study inclusion criteria were a PaO 2 /FiO 2 ratio of less than 350 mm Hg, a cardiac index (CI) of more than 2.5 l/min/m 2 , a dosage of dopamine and/or dobutamine of not more than 10 μg/kg/min, and standard AOM performance (P max , 30—35 cm H 2 O; endexpiratory pressure (PEEP), 13—15 cm H 2 O). Regression analysis was used to identify the predictors of a clinically significant reduction in CI (less than 2.5 l/min/m 2 ). Results . Before and after AOM, CI was 3.1±0.1 and 2.9±0.1 l/min/m 2 , respectively ( p >0.05); however, CI was less than 2.5 l/min/m 2 (2.16±0.09 l/min/m 2 ) in 25% of cases. After AOM, CI values were significantly related to those recorded prior to a respiratory procedure ( p =0.039), total peripheral vascular resistance index (TPVRI) ( p =0.00039), and intrapulmonary blood shunt fraction (Qs/Qt) ( p =0.041). There were no relationships to other record ed and estimated hemodynamic parameters (p>0.1). After AOM, CI values were unrelated (p>0.1) to the duration of extracorporeal circulation, the period of myocardial ischemia, and the used dosages of inotropic agents. The predictor of a clinically significant CI reduction after AOM was the only index TPVRI (p=0.00025) recorded before a respiratory procedure. Following AOM, the probability of a significant CI reduction substantially increased (the approximation coefficient R2=0.75) at TPVRI values of 2000 din•sec•cm-5•m2 or more. Conclusion. After AOM performed in the early period after extracorporeal circulation, CI values are related to the baseline level of CI, TPVRI, and Qs/Qt; however, after this procedure only the value of TPVRI is a reliable predictor of clinically significantly depressed cardiac pump function. The risk of persistent cardiodepression is highest at TPVRI values of 2000 din•sec•cm-5•m2 or more. AOM should be carried out early after extracorporeal circulation in cardiosurgical patients, by making an invasive monitoring that makes it possible to maximally correctly evaluate central hemodynamics, including CI and TPVRI.

Relationship between total peripheral resistance and measures of central artery wave reflection

We examined the relationship between total peripheral resistance (TPR) and central artery pressure and indices of wave reflection in 16 subjects (10F/6M; 26 ± 1 yr). Non‐invasive aortic pressure waveforms were synthesized from high‐fidelity radial pressure waveforms obtained from applanation tonometry of the radial artery. Radial blood pressure (BP) was calibrated from brachial artery BP (catheter). Central artery pressures, aortic augmentation index (AIa), roundtrip travel time of the reflected wave to and from the periphery (Δtp; inverse of pulse wave velocity), and wasted left ventricular energy (Ew) were calculated from the generated aortic pressure waveform. Cardiac output (CO) was measured using an open‐circuit acetylene uptake technique and used to calculate total peripheral resistance (mean arterial pressure/CO). TPR was positively related to aortic pulse pressure (r = 0.49), augmented pressure of the central artery wave (r = 0.60), pulse pressure amplification (r =0.54), AIa (r = 0.53), and Ew (r = 0.66), (P &lt; 0.05 for all). Additionally, TPR was inversely related to Δtp (r = − 0.51, P &lt; 0.05). Our data suggests that increased levels of TPR are related to measures of central artery pressure, wave reflection characteristics and indices of central artery stiffness.Supported by NIH K23 DK‐082424 (TBC), AHA 2170087(ECH) and CTSA RR‐024150