Systemic Vascular Resistance Values Research Articles

Impact of Ayurveda-based lifestyle modification, diet, and panchakarma on the hemodynamic parameters in heart failure patients with preserved ejection fraction

Abstract Background: Heart failure (HF) with preserved ejection fraction (HFpEF) is a medical problem with a growing prevalence that requires sophisticated management techniques. New management strategies for HF have constantly been called for by researchers, which has drawn our attention to Ayurveda, the traditional alternative medicine practiced extensively in India. One such treatment used to treat heart failure is Heart Failure Reversal Therapy (HFRT), which combines herbal therapies including Snehan, Swedan, Basti (per rectal drug administration), and Hridaydhara. Objective: The study is aimed to evaluate the effects of HFRT and Ayurveda Dinacharya on known chronic HFpEF patients. Materials and Methods: This observational study was conducted between May 2021 and October 2021, wherein patients (both genders) with HF (New York Heart Association, NYHA Class I, II, and III) having a left ventricular ejection fraction of more than 40 and aged between 18 and 60 years were identified. The effect of study therapy, HFRT, and Ayurveda Dinacharya over 7 days in 14 sittings was observed. A total of 73 patients with HFpEF underwent study therapy for 7 days. Data related to patient demographics on Cardiac Output (CO), Diastolic Blood Pressure (DBP), Heart Rate (HR), Left Ventricular (LV), Systolic Blood Pressure (SBP), Systemic Vascular Resistance (SVR), Systolic (SYS), End-diastolic volume (EDV), Ejection factor (EF), etc. were analyzed pre- and post-study. Results: There was a remarkable improvement in the mean values of SVR from day 1 to day 7. The mean value of SVR on day 1 was 2271.39 ± 509.66, and on day 7 was 1876.18 ± 315.21. Reduced SVR values mean the amount of LV force needed to open the aortic valve is also reduced. This causes more efficient pumping action in the left ventricle, reflected by increased CO and increased VO2 max, thus improving the quality of life. Conclusion: The HFRT therapy and Ayurveda Dinacharya for seven days demonstrated a significant change in the hemodynamics of HFpEF patients, thus improving the quality of life.

Evaluating the intraoperative changes in several hemodynamic parameters using uscom method in severe burn patients undergoing burn necrotomy, skin grafting

Objective: To evaluate the intraoperative changes in some hemodynamic parameters by the USCOM method in severe burn patients undergoing burn necrotomy, skin grafting.Subjects and methods: 30 severe burn patients, aged 16-60, treated at the Emergency Department, National Burn Hospital, were scheduled for necrosis and skin grafting from May 2023 to December 2023. Cross-sectional, clinical descriptive study.Results: CO and CI values at all study times were within normal limits (3.5-8 l/min and 2.4-4.2 l/min/m2). CO and CI were highest at the time of pre-medication (6.93 and 4.24) and lowest at the time of skin grafting (5.87 and 3.61). SVR values at all times were within normal limits (800 - 1600 d.s.cm-5). SVR was highest at the time the patient was awake (1278.33) and lowest at the time immediately after induction of anesthesia (976.93). SVRI values at 3 times after induction of anesthesia, before necrotomy, and at the time of necrotomy were lower than normal values (1800-3200 d.s.cm-5.m2). SVI at the remaining time points was within normal limits. SV values at all times were within normal ranges (50-110 cm3). SVI values at most times were smaller than normal values (35 - 65 ml/m2), except for at the time of necrotomy (35.03). SVV values at all times were higher than normal (< 20%).Conclusion: Stroke volume variation (SVV) parameters at all study times were higher than normal values corresponding to the age range. The stroke volume index parameter SVI at most times was lower than the normal value, and SVRI at all times was not higher than the normal value. However, the parameters cardiac output (CO), cardiac index (CI), stroke volume (SV), and systemic vascular resistance (SVR) were all within the range of normal values corresponding to the age range at the research time points.

Comparative investigation of pulmonary vasodilating effects of inhaled Nitric Oxide (NO) gas therapy and inhalation of SIN-1, a new drug formulation containing an NO-donor metabolite

Abstract Background The management of acute pulmonary hypertension has recently been in the center of attention as Coronavirus Disease 2019 (COVID-19) might lead to acute respiratory distress syndrome associated with hypoxia-induced pulmonary vasoconstriction. Therefore inhalation therapy has been the object of several clinical trials. Purpose In this experimental study we aimed at investigating the hemodynamic effect of inhalative SIN-1a (3-morpholino-syndnonimine, the unstable active metabolite of molsidomine, stabilized by cyclodextrine) administration during physiological and pathological conditions in a large animal model. Methods Landrace pigs were randomized into the following experimental groups: iNO (inhaled nitric-oxide, n=3), SIN-1-5 (5 mg, n=3), SIN-1-10 (10 mg, n=3). Hemodynamic parameters were recorded after parallel insertion of PiCCO system and Swan-Ganz catheter. The effect of iNO and SIN-1 inhalation (30 min) was investigated under physiologic conditions and U46619, a thromboxane-receptor agonist induced pulmonary hypertension. Results The observed alterations after inhalation therapy were quite similar under physiological and pathological condition. Pulmonary arterial pressure (PAP) was decreased by all of these drugs, SIN-1-10 had similar effect as iNO (physiological contidiont: -36.1% iNO, -23.8% SIN-1-5, -35.5% SIN-1-10; U46619-induced pulmonary hypertension: -30.1% iNO, -22.1% SIN-1-5, -31.2% SIN-1-10). While iNO therapy did not influence the mean arterial pressure (MAP) and systemic vascular resistance (SVR) values, SIN-1 administration resulted in decreased MAP and SVR values. Pulmonary vascular resistance (PVR) was decreased by iNO greater than with using SIN-1. As a result of these alterations, the PVR/SVR ratio decreased markedly in the iNO group, while it was stepwisely increased in the SIN-1-5 and SIN-1-10 group. Conclusion The pulmonary vasodilator effect of SIN-1 was dose dependent, and in case of larger dose it was comparable to that of iNO. However, the vasodilatory effects of SIN-1 inhalation was not limited to the pulmonary circulation, a significant and dose-dependent systemic vasodilation could also be documented.

Associated factors and hemodynamic characteristics of resistant hypertension in the elderly.

The purpose of this study was to explore the associated factors and hemodynamic characteristics of resistant hypertension (RHTN) in the elderly. A total of 283 patients aged ≥60 years with hypertension were evaluated by the CNAP™ monitor. Among them, 240 patients were non-RHTN (controlled hypertension with use of three or fewer antihypertensive medications) and 43 patients were RHTN (uncontrolled hypertension despite the concurrent use of ≥3 antihypertensive drugs at optimized doses, including a diuretic, or achieving target blood pressure with the use of ≥4 antihypertensive medications). RHTN was associated with higher body mass index (BMI), longer hypertension duration, and coronary heart disease (p=.004, p<.001, and p=.042, respectively). The mean number of antihypertensive medications was greater in patients with RHTN (p<.001). Hemodynamic analysis revealed higher cardiac output in the RHTN group than in the non-RHTN group, while no difference was observed in systemic vascular resistance. Screening for secondary etiology showed that, among the 43 patients with RHTN, 8 (18.6%) had chronic kidney disease, 8 (18.6%) had obstructive sleep apnea, 4 (9.3%) had primary aldosteronism, 2 (4.7%) had renovascular disease. No significant differences were observed in the cardiac output and systemic vascular resistance values between different causes of RHTN. These findings suggest that higher body mass index, longer hypertension duration, and coronary heart disease emerged as the associated factors of RHTN in the elderly. RHTN is characterized by higher cardiac output. Screening for the possible secondary etiology of RHTN in the elderly patients is necessary and important.

376 Maternal age impact on hemodynamic monitoring at delivery evaluated by a novel non-invasive PPG-based sensor

Age influence maternal hemodynamics and adaptation during labor and delivery. We utilized an innovative, noninvasive, reflective PPG-based device (Biobeat Technologies Ltd.) that enables continuous monitoring to assess cardiovascular changes during labor and delivery stratified by maternal age. The Biobeat Monitoring Platform includes a wearable wristwatch monitor, that automatically samples cardiac output (CO), blood pressure (BP), stroke volume (SV), systemic vascular resistance (SVR) and heart rate (HR) every 5 seconds and uploads all data to a smartphone-based app and to a data cloud, enabling remote monitoring and analysis of data. Low risk parturients carrying term, singletons pregnancies were recruited at early delivery. Big data analysis was performed using the Power BI analysis tool (Microsoft). Data was normalized to visual presentation using Excel Data Analysis and regression tool. Average measurements were compared 20 minutes before and after epidural anesthesia and fetal delivery, stratified by maternal age. 81 parturients were recruited (26 nullipara; BMI 29.7±5.1,Kg/m2) and allocated to study (≥ 35 years, 17/81, 21%, mean age 36.7±2) and control group (<35 years, 64/81, 79%, mean age 28.6±3.2). Over 800,000 measurements were retrieved. During labor and around epidural anesthesia study group had lower CO, SV and HR values. MAP was also lower despite higher SVR values (for example: mean CO 5.1 to 5 for study group vs. 5.5 to 5.6 for control group, L/min, 20 minutes before and after epidural, p<0.05 for all, Fig 1). Same trend continued at delivery with lower CO, HR, SVR, MAP and higher SVR values for study group (for example: mean CO 5.9 to 6.8 to 5.8 for study group vs. mean CO 6.1 to 7.3 to 6.5 for control group, L/min, 20 minutes before, at peak and after delivery, p<0.05 for all, Fig 2). Both epidural and delivery were associated with statistical significant changes for most parameters, however, not all differences had clinical significance. Maternal age influences hemodynamic adaptation during labor and delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Effects of general anesthesia of sevoflurane inhalation on perioperative blood gas indicators in patients with mild-to-moderate chronic obstructive pulmonary disease

Objective To explore the clinical effects of general anesthesia of sevoflurane inhalation in abdominal surgery for patients with mild-to-moderate chronic obstructive pulmonary disease (COPD). Methods The clinical data of 68 patients with COPD abdominal surgery who admitted to the Department of Anesthesiology of Yiwu Central Hospital from June 2016 to June 2018 were retrospectively analyzed.According to the ratio of forced expiratory volume in 1 second in predicted value (FEV1%pre), the patients were divided into mild group (FEV1%pre≥80%, n=39) and moderate group (80%>FEV1%pre≥50%, n=29). The blood gas indicators[arterial partial pressure of oxygen (PaO2), arterial partial pressure of blood carbon dioxide (PaCO2), blood oxygen saturation (SaO2)], vital signs[heart rate (HR), mean arterial pressure (MAP)] and systemic vascular resistance (SVR) were compared between the two groups after entering (T0), after completion of induction (T1), at abdominal exploration (T2), before the end of surgery (T3) and after extubation (T4). The recovery quality indicators were analyzed in the two groups. Results In the mild group at T1, T2 and T3, the PaO2 values were (301.6±76.2)mmHg, (292.6±73.4)mmHg, (112.8±34.1)mmHg, respectively, and the SaO2 values were (99.1±0.8)%, (98.8±1.0)%, (94.5±2.2)%, respectively, all of which were significantly improved compared with those at T0 (t=23.51, 22.73, 12.34, 2.75, 2.93, 2.22, all P 0.05). At T4, the PaO2, PaCO2 and SaO2 levels in the two groups showed no significant changes compared with those at T0, and there was no statistically significant difference between the two groups at the same time (all P>0.05). At T1 and T2, the MAP levels in the mild group were (75.5±11.0)mmHg, (80.7±11.9)mmHg, respectively, the HR values were (71.4±12.5)times/min, (74.2±13.6)times/min, respectively, the SVR values were (9.1±1.6)×102 dynesos-1ocm-5, (9.9±2.0) ×102 dynesos-1ocm-5, which were significantly lower than those at T0 (t=1.35, 0.95, 1.83, 0.64, 1.42, 0.27, all P 0.05). At T3 and T4, there were no significant changes in levels of MAP, HR and SVR between the two groups compared with those at T0, and there were no significant significant differences between the two groups (all P>0.05). The spontaneous breathing time, duration of eye opening, time of fist, time of removing tracheal catheter and time of returning to the ward in the mild group were slightly shorter than those in the moderate group (all P>0.05). Conclusion When general anesthesia of sevoflurane inhalation is used in abdominal surgery of COPD patients, the trend of blood gas indicators is not affected by COPD, which can provide reference for clinical establishment of anesthesia regimens. Key words: Sevoflurane; Anesthesia, general; Pulmonary disease, chronic obstructive; Abdominal surgery; Blood gas indexes; Expiratory volume; Vital signs; Recovery quality index

Comparison of fentanil and remifentanil for coronary artery surgery with low ejection fraction.

IntroductionIn this study, we evaluated patient response and haemodynamic parameters in patients with low ejection fraction undergoing coronary bypass surgery with either fentanil or remifentanil in conjunction with etomidate.Material and methodsWe evaluated 30 cases of coronary artery surgery, which were divided into two treatment groups (n = 15 each). In group F (fentanil group), the following regimen was employed for anaesthesia induction: 1 mg/kg lidocaine, 0.3 mg/kg etomidate, and, following a 1 µg/kg 60 s bolus dose of fentanil, a 0.1 µg/kg/min fentanil infusion was initiated, after which 0.6 mg/kg rocuronium was administered. In group R (remifentanil group), the following regimen was employed for anaesthesia induction: 1 mg/kg lidocaine, 0.3 mg/kg etomidate and, following a 1 µg/kg 60 s bolus dose of remifentanil, a 0.1 µg/kg/min remifentanil infusion was initiated, after which 0.6 mg/kg rocuronium was administered. Systolic artery pressure, diastolic artery pressure, mean arterial pressure, heart rate, SPO2 (saturation), cardiac output, stroke volume variance, central venous pressure, and systemic vascular resistance values were recorded for all study patients at five minutes before anaesthetic induction (T1), immediately following induction (T2), and immediately following intubation (T3).ResultsThe demographic values obtained for both groups were similar. We found that remifentanil use was associated with decreased cardiac output and increased fluctuations in both heart rate and mean values of arterial pressure.ConclusionsAlthough many studies have demonstrated remifentanil to be as safe as fentanil when titrated to an appropriate dose, our study suggests that fentanil may be a more appropriate choice during the induction of anaesthesia in patients with a low ejection fraction.

Aerobic training session length affects arterial elasticity.

The purpose of this study was to examine haemodynamic and arterial elasticity responses to aerobic exercise of varying durations. Eighteen male subjects (age=23·4±2·0) performed a maximal aerobic fitness (VO2max ) test. Participants met in the laboratory following an overnight fast for three randomly assigned sessions. Assessments for large and small arterial elasticity (SAE), systemic vascular resistance (SVR), total vascular impedance (TVI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), pulse pressure (PP) and cardiac ejection time (CET) were performed using applanation tonometry at the radial artery. Following baseline measurements, participants executed aerobic exercise on a treadmill at 65% of their respective VO2max for 30, 45 or 60min on three different occasions. Postexercise measurements were performed immediately, 10, 20 and 40min postexercise cessation. The 60-min exercise bout resulted in significantly increased SAE values (P<0·04) and decreased SVR values (P<0·02) when compared with the 30-min exercise bout. The 60-min session also caused significantly higher HR values and significantly lower values for SV and DBP values following exercise (P<0·04). The results of this study emphasize that varying the length of moderate-intensity aerobic exercise bouts affects arterial elasticity response and total vascular resistance.

Maternal hemodynamics in normal pregnancy: reference ranges and role of maternal characteristics.

The main aim of this study was to construct reference ranges of maternal central hemodynamic parameters during pregnancy. The second aim was to determine the maternal and pregnancy characteristics that influence these hemodynamic parameters. This was a prospective cohort study of low-risk pregnant women attending for routine antenatal care at St George's Hospital, London, UK. Exclusion criteria included any medical disorder present at the time of study recruitment, or development of hypertension or intrauterine fetal growth restriction following study recruitment. Stroke volume (SV), cardiac output (CO) and systemic vascular resistance (SVR) were obtained using non-invasive cardiac output monitoring (USCOM-1A®). USCOM-1A utilizes a non-imaging probe in the suprasternal notch to obtain velocity-time integrals of transaortic blood flow at the left ventricular outflow tract. Once the distribution of the data with respect to gestational age had been determined, maternal characteristics were added to the model to test whether they provided a significant improvement in the prediction of the median value. The study included 627 women with a singleton pregnancy. The estimated median CO was constant for a maternal age above 32 years, but was around 0.5 L/min higher for women aged ≤ 25 years (P < 0.001). Maternal weight (P < 0.001) and height (P < 0.001) significantly affected CO values and there was a significant interaction (P = 0.002) between them. In women with a height of less than 1.60 m, there was no association between median CO and weight; however, in those with a height exceeding 1.60 m, an increase in weight was associated with an increase in CO. SV was primarily associated with height (P < 0.001), although some positive association with weight (P < 0.001) could also be observed within the normal body-mass-index range. Greater height (P < 0.001) was associated with lower median values of SVR, with an estimated difference of around 120 dynes × s/cm5 between 1.60 m and 1.80 m. Advancing maternal age was associated with higher median SVR, with an estimated difference of around 50 dynes × s/cm5 between 25 and 35 years. Smokers had a lower SVR by 73.5 (95% CI, 8.6-138.4) dynes × s/cm5 . Maternal hemodynamics are influenced significantly by maternal age, height and weight. We provide USCOM-1A-specific reference ranges and a calculator for SV, CO and SVR in uncomplicated pregnancies that correct for maternal age, height and weight. This should enable clinical application and comparison in both uncomplicated and pathological pregnancies. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Non-invasive characterization of hemodynamics in adult out-of-hospital cardiac arrest patients soon after return of spontaneous circulation

BackgroundLittle is known about hemodynamics in adult, out-of-hospital (OHCA) patients following return of spontaneous circulation (ROSC). A 1994 study when “high-dose epinephrine” use was common showed consistently elevated systemic vascular resistance (SVR) lasting ≥6 h in 49 adult patients after return of spontaneous circulation (ROSC). Study aimTo characterize hemodynamic abnormalities in adult OHCA patients soon after ROSC. Our hypothesis was that, unlike the consistently high SVR values reported when “high-dose” epinephrine was in common use, there would be a more heterogenous distribution of SVR values using current adrenergic therapy. MethodsWe included adult, OHCA patients transported by paramedics to the Emergency Department (ED) post-ROSC. Children, prisoners, pregnant women, and those with ongoing CPR or arrest due to traumatic injury were excluded. Hemodynamics were recorded non-invasively as soon as feasible after ED arrival but were not used to influence therapy, which was guided by clinical judgment of treating ED physicians. ResultsHemodynamics were recorded on 30 patients 20 [16,25] minutes after ED arrival: 50% had a normal SVR, 30% had a high SVR, and 20% had a low SVR. There was no difference in survival to admission among groups, although there was a difference among groups in survival to discharge. Comparing the low SVR group vs the combined normal and high group revealed a trend for fewer 0/6 (0%) low vs. 10/24 (42%) normal or high SVR patients surviving to hospital discharge (p = .053). ConclusionA heterogeneous range of hemodynamic states exist post-ROSC rather than consistent vasoconstriction. Adequately powered, randomized clinical trials will be needed to determine whether noninvasively-derived, hemodynamic-directed therapy can play a role in improving neurologically-intact survival following OHCA in adults.

Correlation between time lag of arterial–plethysmographic waveforms and systemic vascular resistance: a prospective study

Blood pressure (BP), a surrogate of cardiac output (CO), is also dependent on systemic vascular resistance (SVR). But SVR is not routinely monitored in daily clinical practice. We hypothesise that the time difference between the peripheral arterial waveform and the finger plethysmographic waveform (time lag index - TLi) could indicate the systemic vascular resistance. In this study, we correlated TLi with the systemic vascular resistance measured by minimally invasive CO monitor (pulse contour analysis). SVR changes in response to administration of mannitol were studied. American Society of Anesthesiologists (ASA) class I and II patients undergoing major intracranial surgeries were recruited. Arterial cannulation and pulse-oximetry recordings were done in the same limb. Arterial and plethysmographic waveforms were recorded before mannitol infusion (baseline) and at every 10 minutes for 60 minutes after the termination of mannitol infusion. Simultaneously, SVR was recorded from the Vigileo FLotrac CO monitor. Using custom-made programme, the time difference between both waveforms was calculated and corrected for heart rate (TLi). The correlation between time lag and the systemic vascular resistance was assessed using a mixed effect model, adjusting for the subject. Data of one hundred subjects were analysed. Following mannitol administration, there was a significant decrease in the SVR and the TLi (p < .001). The patient characteristics influenced both the baseline values of SVR (intercept) and the changes in SVR over time (slope). As both the baseline value and the change over time for SVR were different in each patient, we used mixed effect model analysis to assess the relationship between SVR and TLi for different time periods. The effect of TLi on SVR was significant (β = 877.16, p = .008). The high beta coefficient suggests that when SVR increases, the TLi also increase and vice versa. A strong correlation between SVR and TLi was demonstrated for a given patient. Further studies are needed to explore the possibility of utilising this parameter to follow up changes in SVR in an individual patient at a particular point in time in different clinical scenarios.

Abstract P427: Inhibition of the Regulator of G Protein Signaling 14, a Novel Anti-Hypertensive Mechanism

The Regulator of G Protein Signaling 14 (RGS14) knockout (KO) mouse is unique in that it not only extends longevity, but also enhances several aspects of healthful aging. The RGS14 KO mouse, compared with wild type (WT), is protected against obesity and diabetes, and has increased exercise capacity, similar to levels achieved with chronic exercise training, all potentially important anti-hypertensive mechanisms. The goal of this investigation was to test more directly that the RGS14 KO mouse is protected against hypertension. Accordingly, we chronically infused angiotensin II (1.44 mg/kg/day) by implanted osmotic pump for 14 days. Stroke volume was measured by cardiac echocardiography. Cardiac output was calculated as the product of stroke volume and heart rate. Heart rates were not different in WT and RGS14 KO prior to angiotensin II infusion or after infusion (425±11 beats/min in WT vs. 420±13 beats/min in KO). Prior to angiotensin II baseline values for mean arterial pressure were similar in WT (84±3 mmHg) and RGS14 KO (79±2 mmHg) and baseline values for systemic vascular resistance, calculated as mean arterial pressure/cardiac output, were also similar in WT (3.7±0.1 mmHg/mL/min) and RGS14 KO (2.2±0.2 mmHg/mL/min) before angiotensin II infusion. As expected, the angiotensin infusion for 14 days increased mean arterial pressure by 69±8 % and systemic vascular resistance by 43±9 % in WT. Surprisingly, angiotensin II failed to increase either mean arterial blood pressure or systemic vascular resistance significantly in RGS14 KO mice. Thus the increases in arterial pressure and vasoconstriction, pathognomonic of angiotensin II, were completely blocked in the RGS14 KO mouse, implicating this mechanism as a potential novel therapeutic modality for treating hypertension.

Abstract 071: An Attenuated Nocturnal Dip in Systemic Vascular Resistance is Associated With Increased Left Ventricular Mass

Introduction: Previous work from our laboratory has demonstrated that the nocturnal “dip” in blood pressure (BP) is due primarily to a decrease in systemic vascular resistance (SVR), and that nondipping is associated with a blunted nighttime reduction in SVR. In this analysis, we examined the hypothesis that a blunted nocturnal SVR fall is associated with increased LV mass. Methods: 24-hour ambulatory hemodynamics were assessed in a biracial sample of 116 men and women with elevated clinic BP (130-159/80-99 mmHg). Ambulatory BP monitoring was coupled with synchronized measurements of cardiac output by ambulatory impedance cardiography. Values for SVR were derived for each ambulatory BP measurement. Left ventricular (LV) mass was measured by echocardiography and indexed by height 2.7 to adjust for differences in body size. Multivariable regression models were used to examine the relationships between LV mass index and demographic characteristics, anthropomorphic variables, daytime ambulatory systolic BP, and dipping of SVR and systolic BP. Results: The study cohort averaged 45.3 ± 8.3 years of age; 42% (49 of 116) of the subjects were female and 47% (54 of 116) were African American. The mean body mass index (BMI) was 28.3 ± 3.8 kg/m 2 . The mean daytime ambulatory systolic BP was 137 ± 11 mmHg; the systolic BP dip averaged 13 ± 5%, and the nocturnal fall in SVR averaged 13 ± 15%. In a model that included age, sex, race, BMI, and daytime systolic BP, daytime systolic BP was significantly associated with LV mass index (b=0.33, p=0.0004). The SVR percent dip, (b=-0.21, p=0.02) but not the percent dip in systolic BP (b=-0.15, p=0.11), was an independent predictor LV mass index when added to this model. Conclusions: A blunted nocturnal dip in SVR is associated with increased LV mass index, independent of daytime systolic BP. This finding suggests that an attenuated nighttime fall in SVR may contribute to left ventricular hypertrophy.

Comparing the Rates of Dopamine Hemodynamic Effect Onset after Infusion through Peripheral Veins in Three Regions.

Background Dopamine is an inotropic agent that is often selected for continuous infusion. For hemodynamic stability, the rate of infusion is controlled in the range of 5-15 μg/kg/min. This study aimed to compare the time intervals from the administration of dopamine to the onset of its hemodynamic effects when dopamine was administered through three different peripheral veins (the cephalic vein [CV], the great saphenous vein [GSV], and the external jugular vein [EJV]).Methods Patients in group 1, group 2, and group 3 received dopamine infusions in the CV, GSV, and EJV, respectively. A noninvasive continuous cardiac output monitor (NICCOMO™, Medis, Ilmenau, Germany) was used to assess cardiac output (CO) and systemic vascular resistance (SVR). Six minutes after intubation, baseline heart rate (HR), systolic blood pressure (BP), diastolic BP, mean arterial pressure (MAP), CO, and SVR values were recorded and dopamine infusion was initiated at a dose of 10 μg/kg/min. Hemodynamic changes at 0, 4, 8, 12, and 15 minutes postinfusion were recorded.Results No statistically significant differences were observed among the three groups with respect to the rate of hemodynamic change. In all groups, systolic BP, diastolic BP, MAP, and SVR tended to increase after decreasing for the first 4 minutes; in contrast, HR and CO decreased until 8 minutes, after which they tended to reach a plateau.Conclusions For patients under general anesthesia receiving dopamine at 10 μg/kg/min, there were no clinical differences in the effect of dopamine administered through three different peripheral veins.

Noradrenalin effectively rescues mice from blast lung injury caused by laser-induced shock waves

BackgroundBlast lung injuries (BLI) caused by blast waves are extremely critical in the prehospital setting, and hypotension is thought to be the main cause of death in such cases. The present study aimed to elucidate the pathophysiology of severe BLI using laser-induced shock wave (LISW) and identify the initial treatment.MethodsThe current investigation comprised two parts. For the validation study, mice were randomly allocated to groups that received a single shot of 1.2, 1.3, or 1.4 J/cm2 LISW to both lungs. The survival rates, systolic blood pressure (sBP), heart rate (HR), peripheral oxyhemoglobin saturation (SpO2), and shock index were monitored for 60 min, and lung tissues were analyzed histopathologically. The study evaluated the effects of catecholamines as follows. Randomly assigned mice received 1.4 J/cm2 LISW followed by the immediate intraperitoneal administration of dobutamine, noradrenalin, or normal saline. The primary outcome was the survival rate. Additionally, sBP, HR, SpO2, and the shock index were measured before and 5 and 10 min after LISW, and the cardiac output, left ventricular ejection fraction, and systemic vascular resistance (SVR) were determined before and 1 min after LISW.ResultsThe triad of BLI (hypotension, bradycardia, and hypoxemia) was evident immediately after LISW. The survival rates worsened with increasing doses of LISW (100 % in 1.2 J/cm2 vs. 60 % in 1.3 J/cm2, 10 % in 1.4 J/cm2). The histopathological findings were compatible with those of human BLI. The survival rate in LISW high group (1.4 J/cm2) was highest in the group that received noradrenalin (100 %), with significantly elevated SVR values (from 565 to 1451 dyn s/min5). In contrast, the survival rates in the dobutamine and normal saline groups were 40 and 10 %, respectively, and the SVR values did not change significantly after LISW in either group.ConclusionsThe main cause of death during the initial phase of severe BLI is hypotension due to the absence of peripheral vasoconstriction. Therefore, the immediate administration of noradrenalin may be an effective treatment during the initial phase of severe BLI.

Effectiveness of prophylactic levosimendan in high-risk valve surgery patients : cardiovascular topics

Levosimendan has anti-ischaemic effects, improves myocardial contractility and increases systemic, pulmonary and coronary vasodilatation. These properties suggest potential advantages in high-risk cardiac valve surgery patients where cardioprotection would be valuable. The present study investigated the peri-operative haemodynamic effects of prophylactic levosimendan infusion in cardiac valve surgery patients with low ejection fraction and/or severe pulmonary arterial hypertension. Between May 2006 and July 2007, 20 consecutive patients with severe pulmonary arterial hypertension (systolic pulmonary artery pressure ≥ 60 mmHg) and/or low ejection fraction (< 50%) who underwent valve surgery in our clinic were included in the study and randomised into two groups. Levosimendan was administered to 10 patients in group I and not to the 10 patients in the control group. Cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (MPAP) were recorded for each patient preoperatively and for 24 hours following the operation. CO and CI values were higher in the levosimendan group during the study period (p < 0.05). MPAP and PVR values were significantly lower in the levosimendan group for the 24-hour period (p < 0.05) and SVR values were significantly lower after 24 hours in both groups. When clinical results were considered, no difference in favour of levosimendan was detected regarding the mortality and morbidity rates between the groups. Levosimendan improved the haemodynamics in cardiac valve surgery patients with low ejection fraction and/or severe pulmonary arterial hypertension, and facilitated weaning from cardiopulmonary bypass in such high-risk patients when started as a prophylactic agent.

The relationship between the area of peripherally-derived pressure volume loops and systemic vascular resistance

Arterial and photoplethysmographic (PPG) waveforms have been utilized to non-invasively estimate stroke volume from the pulse contour. The ability of these pulse contour devices to accurately predict stroke volume is degraded when afterload changes significantly. There is a need for a non-invasive device capable of identifying when vascular tone has changed. Shelley et al. previously described a qualitative relationship between peripheral pressure volume (PV) loops (in which pressure waveforms from an intra-arterial catheter are combined with volume waveforms from the PPG waveform) and changes in vascular tone. The purpose of this study was to quantitatively compare changes in the area of peripheral PV loops with changes in systemic vascular resistance (SVR) in a patient population undergoing major surgery. Physiologic data from ten patients undergoing liver transplantation was extracted from a hemodynamic database. A peak detection algorithm was applied to both the arterial and PPG waveforms, which were manually aligned so that the troughs occurred at identical time points. PV loop area (PVA) for each heartbeat was calculated and median PVA was recorded for each minute. PVA for each patient was indexed to the average value for the first 5min (because PPG amplitude has no standard and is not comparable between patients) and compared to indexed SVR at all points for which SVR was available. SVR and PVA were plotted as a function of time and outliers (3.1%) removed. The Pearson correlation coefficient describing the relationship between PVAi and SVRi was 0.67 (1,728min of data, p=0.0020, sign test over 10 patients) and between MAP and SVR was 0.71. There was no meaningful correlation between ΔSVR and either ΔPVA or ΔMAP (based on minute-to-minute changes). Indexed values of PVA are correlated with indexed values of SVR and may serve as a useful monitor for changes in afterload but in their present form do not offer added value above the measurement of MAP. Incorporation of different (e.g. finger, forehead) and redundant (e.g. bilateral) sites may significantly improve the accuracy of this technique.

Does intravenous landiolol, a β1-adrenergic blocker, affect stroke volume variation?

There are no reports about the effect of bradycardia on stroke volume variation (SVV), and we hypothesized that induced bradycardia alters the value of SVV. Landiolol, an ultra-short-acting adrenergic β1-receptor blocking agent, was reported to induce bradycardia without decreasing blood pressure. The initial aim of this prospective study was to investigate changes in SVV values by induced bradycardia in patients with good cardiac function. At 30 min after anesthesia induction, if heart rate (HR) was >80 bpm, the patient was chosen as a subject. Ten ASA physical status I-II patients aged 38-75 years who were scheduled for elective abdominal surgery were included in this study. Baseline values were recorded, and then administration of landiolol was started at 125 μg/kg/min for 1 min and then continued at 40 μg/kg/min. SVV and other parameters were recorded at baseline and 3 min after continuous landiolol injection. Landiolol significantly decreased systolic arterial pressure, and diastolic arterial pressure, contrary to our expectations, and also HR, SVV, cardiac output, stroke volume index, and pressure of end-tidal CO(2), whereas systemic vascular resistance values increased significantly. SVV decreased after continuous administration of a β1-adrenergic blocker, probably because of a decrease in the difference of maximum stroke volume (SV) and minimum SV, or the downward shift of the Frank-Starling curve that occurred after landiolol administration. We believe that SVV values might be overestimated or misinterpreted when HR is decreased by landiolol and might not necessarily indicate that the patient is hypervolemic or normovolemic.

THIS ARTICLE HAS BEEN RETRACTED: Haemodynamic derangement in human immunodeficiency virus-infected patients with hepatitis C virus-related cirrhosis: the role of bacterial translocation

Background and aims: Analysis of the influence of the effects of increased intestinal permeability on haemodynamic alterations in human immunodeficiency virus (HIV)-infected patients with decompensated hepatitis C virus (HCV)-related liver disease. Methods: Forty HIV/HCV co-infected patients and 40 HCV mono-infected patients, 20 of them with compensated cirrhosis and 20 with a previous decompensation, and 20 healthy controls, were studied. Intestinal permeability was determined by serum levels of lipopolysaccharide-binding protein (LBP). Monocyte expression of toll-like receptor 4 (TLR-4), serum levels of interleukin (IL)-6 and soluble receptors of tumour necrosis factor (sTNFRI) were analysed. Cardiac index, systemic vascular resistance (SVR), plasma renin activity (PRA) and aldosterone concentration were also determined in cirrhotic patients. Results: Serum levels of LBP, TLR-4, IL-6 and sTNFRI were significantly higher in HIV–HCV co-infected and HCV mono-infected patients with decompensated cirrhosis compared with those with compensated liver disease. Significantly lower values of SVR and higher values of cardiac index, PRA and aldosterone concentration were observed in patients with decompensated cirrhosis compared with those with compensated liver disease, particularly in those with elevated levels of IL-6. There were no significant differences between HIV/HCV co-infected and HCV mono-infected patients. Conclusions: Higher intestinal permeability and consequent macrophage activation is observed in patients with cirrhosis; this permeability is even higher in those with portal hypertension. Serum values of IL-6 are associated with the characteristic haemodynamic derangement observed in advanced phases of cirrhosis. HIV/HCV co-infected cirrhotic patients present inflammatory and systemic haemodynamic alterations similar to those observed in HCV mono-infected patients.

Myocardial Protection in Patients Undergoing Coronary Artery Bypass Grafting Surgery Using Minimized Extracorporeal Circulation in Combination With Volatile Anesthetic

The minimized extracorporeal circulation (ECC) is a safe alternative for coronary artery bypass grafting (CABG) and allows a reduction of the negative effects associated with conventional extracorporeal circulation. Experimental and clinical data indicate that the anesthetic regime might influence the ischemia-reperfusion injury in CABG surgery. The aim of our retrospective study was to investigate the cardioprotective effects of two different minimized ECC systems in combination with two different anesthetic concepts and to determine the impact on oxygen consumption during aortic cross-clamping (ACC). Data of 1,182 patients who underwent elective isolated CABG with minimized ECC from January 1, 2003, to December 31, 2008, were enrolled in a retrospective manner. Patients were allocated either to sevoflurane-based volatile anesthesia using PRECiSe system (SEVO group) or to propofol-based intravenous anesthesia using MECC system (PROP group). Postoperatively, the SEVO group showed lower concentrations of myocardial fraction of creatine kinase compared with the PROP group (p < 0.001). During the period of ACC, the values of systemic vascular resistance (SVR) were higher in SEVO group (p < 0.005). Also, the SEVO group showed lower oxygen consumption at each time point ACC (p < 0.0001). In conclusion, PRECiSe system using a microporous capillary oxygenator in combination with sevoflurane-based volatile anesthetic regimen seem to provide lower postoperative myocardial cell damage and to allow improved perfusion with higher SVRs and lower oxygen consumption during ACC.